According to the research report by the Council of Europe1, one of the typologies of money laundering through online gambling is the use of multiple accounts and identities to conceal the source and destination of funds. This can be done by opening several accounts under the same name using different IP addresses, or by using false or stolen identification documents to create multiple accounts. Another typology is the use of online gambling platforms that are not regulated or authorized by the jurisdiction where the customer is located, or that do not require know-your-client information from users. This can allow money launderers to access the online gambling services from multiple countries, without being subject to any verification or monitoring by the authorities.
1: Research report - The use of online gambling for money laundering and the financing of terrorism purposes, Council of Europe, April 2013.

According to the ACAMS CAMS Study Guide, 6th Edition, Chapter 4, Section 4.2, the AML Specialist at a bank should take the following actions upon receiving a confidential alert from law enforcement about suspected money launderers:
Involve the bank's legal and compliance function to address the gravity of the matter and ensure that the bank' s response is appropriate and lawful. The legal and compliance function can also advise on the bank's obligations and rights under the relevant laws and regulations, such as the General Data Protection Regulation (GDPR), the Bank Secrecy Act (BSA), and the USA PATRIOT Act.
Perform a search on the bank's client data platform to determine if the bank has had any business with the named individuals or any related parties. The search should include current and past accounts, transactions, wire transfers, and other relevant records. The AML Specialist should also review any existing customer due diligence (CDD) and enhanced due diligence (EDD) information on the potential suspects and update them as necessary.
The other options are not recommended or required actions for the AML Specialist at a bank in this scenario:
Sending out an email to all of the bank's client advisors to request information on any of the individuals could compromise the confidentiality of the alert and expose the bank to legal and reputational risks. It could also alert the suspects or their associates and hinder the law enforcement investigation.
Reporting findings back to law enforcement only if they are of any significance is not sufficient or compliant with the bank's obligations to cooperate with law enforcement and report any suspicious activity. The AML Specialist should report any relevant information or findings to law enforcement as soon as possible, regardless of their significance, and follow the established procedures and protocols for information sharing and reporting.
Responding to law enforcement that their request without a judicial order would breach the bank's GDPR duty with respect to its clients is not accurate or helpful. The GDPR does not prohibit the bank from sharing personal data with law enforcement for the purposes of preventing, detecting, or investigating money laundering or other criminal activities, as long as the bank has a legal basis and safeguards for doing so. The bank should consult with its legal and compliance function to determine the best way to respond to the law enforcement request and balance its GDPR obligations with its anti-money laundering (AML) duties.
References:
ACAMS CAMS Study Guide, 6th Edition, Chapter 4, Section 4.2
General Data Protection Regulation (GDPR)
Bank Secrecy Act (BSA)
USA PATRIOT Act

According to the Certified Anti-Money Laundering Specialist (CAMS) study guide, 6th edition, page 105, the correct answer is C. It can be difficult to determine if there is negative media associated with counterparties solely from the customer's account activity and KYC file.
The study guide explains that negative media can include news articles, government sanctions lists, and other sources of public information that may indicate that a counterparty is involved in illicit activities. However, this information may not be readily available in a customer's account activity or KYC file, and may require additional research or investigation.

According to the Egmont Group of Financial Intelligence Units, which is a global network of FIUs that promotes information exchange and cooperation, FIUs making requests to another FIU should disclose the reason and purpose for the request, andprovide feedback on how the information was used12. These actions are intended to enhance mutual trust, transparency, and accountability between FIUs, and to facilitate the effective use of financial intelligence and information for combating money laundering, terrorist financing, and other financial crimes12. FIUs making requests should also respect the confidentiality and data protection requirements of the FIU receiving the request, and avoid imposing unreasonable or unduly restrictive conditions12.
FIUs making requests should not send the same request to all FIUs, as this would be inefficient, unnecessary, and potentially harmful. FIUs should only send requests to FIUs that are relevant and competent to provide the information they need, based on the nature and scope of the case12. Sending the same request to all FIUs could overload the system, create duplication, and compromise the security and confidentiality of the information12. FIUs making requests should also make best efforts to provide complete andfactual information, but this is not an action they should take when submitting a request, but rather when responding to a request from another FIU12.
Egmont Group of Financial Intelligence Units Operational Guidance for FIU Activities and the Exchange of Information Principles for Information Exchange Between Financial Intelligence Units

According to the Wolfsberg Principles on Private Banking, the bank should apply additional diligence to customers who present a higher risk of money laundering or other financial crimes. Some of the indicators for defining such customers are:
Persons residing in or having funds from countries with inadequate AML standards, sanctions, embargoes, or other measures that indicate a higher risk of money laundering or terrorist financing12.
Persons engaged in business activities known to be susceptible to money laundering, such as cash-intensive businesses, gambling, arms trade, precious metals and stones, art and antiquities, etc13.
Persons determined to be Politically Exposed Persons (PEPs), who are individuals who hold or have held positions of public trust or influence, or their family members or close associates, and who may pose a higher risk of corruption, bribery, or abuse of power14.
Persons who receive funds from a correspondent banking relationship are not necessarily required additional diligence, unless they fall under any of the above categories or other risk factors. Correspondent banking is a service provided by one bank to another bank to facilitate cross-border transactions, and it is subject to its own set of AML standards and due diligence measures5.
Wolfsberg Anti-Money Laundering Principles for Private Banking (2012) 1 FATF High-Risk and Other Monitored Jurisdictions FATF Money Laundering and Terrorist Financing Vulnerabilities of Legal Professionals FATF Guidance on Politically Exposed Persons (Recommendations 12 and 22) FATF Guidance on Correspondent Banking Services