Explanation:

When a client requests a scope change, such as extending the project radius by 1 km, the project manager should first obtain formal acceptance for the work that has been completed within the original scope.
Following this, the project manager should submit a change request to address the new requirement. This process is in line with the PMBOK Guide's Change Management Process, which includes identifying the change, analyzing its impact, documenting it, and presenting it to the Change Control Board (CCB) for approval1.
:
PMBOK Guide's Change Management Process For PMP Certification1.
Project Management Institute's official references for the PMP certification2.
Professional in Business Analysis Reference Materials provided by PMI2.

In this scenario, the project manager should engage in negotiations to address the conflict of resource allocation. The PMBOK Guide suggests that project managers should possess negotiation skills to resolve such conflicts effectively. By negotiating, the project manager can work towards a solution that satisfies the needs of the operations department while also ensuring the SME's contributions to the project are not lost, thus keeping the project on track.
: The response is based on general project management principles as outlined in the PMBOK Guide and conflict resolution strategies that include negotiation, which are part of the PMP's body of knowledge.

Upon being assigned to a project, especially one as critical as providing water access to a community, the project manager's next step should be to start project planning and develop the project management plan. This is in accordance with the PMBOKGuide's recommended process, which emphasizes the importance of planning in the project management life cycle. The planning phase involves defining the project scope, objectives, and procedures, which are crucial for the successful delivery of the project outcomes. It ensures that all aspects of the project are methodically approached and that the project's goals are aligned with the community's needs.
:
PMBOKGuide - Seventh Edition
The PMI Guide to Business Analysis
Standards & Publications by Project Management Institute

the project manager should communicate the situation to the appropriate stakeholders who are responsible for managing the supplier relationship and contract. The purchasing department can then take the necessary actions to mitigate the risk of supplier failure or default, such as negotiating new terms, finding alternative suppliers, or terminating the contract. The project manager should not add the situation to the risk register (A) or use the issue log (D) without informing the purchasing department first, as this would not address the root cause of the problem or prevent potential impacts on the project. The project manager should not identify competitors (B) without consulting the purchasing department, as this could violate the existing contract or procurement policies. References:
* PMBOK Guide, 7th edition, page 37, section 2.2.6, "Business Environment"
* PMBOK Guide, 7th edition, page 39, section 2.2.7, "Governance"
* PMBOK Guide, 7th edition, page 41, section 2.2.8, "Lifecycle"
* PMBOK Guide, 7th edition, page 43, section 2.2.9, "Tailoring"
* PMBOK Guide, 7th edition, page 45, section 2.2.10, "Models, Methods, and Artifacts"
* PMBOK Guide, 7th edition, page 47, section 2.2.11, "Project Performance"
* PMBOK Guide, 7th edition, page 49, section 2.2.12, "Adaptive Delivery"
* PMBOK Guide, 7th edition, page 51, section 2.2.13, "Project Management Office"
* PMBOK Guide, 7th edition, page 53, section 2.2.14, "Project Team"
* PMBOK Guide, 7th edition, page 55, section 2.2.15, "Stakeholders"
* PMBOK Guide, 7th edition, page 57, section 2.2.16, "Information Management"
* PMBOK Guide, 7th edition, page 59, section 2.2.17, "Principles"
* PMBOK Guide, 7th edition, page 61, section 2.2.18, "Performance Domains"
* PMBOK Guide, 7th edition, page 63, section 2.2.19, "Tailoring and Models"
* PMBOK Guide, 7th edition, page 65, section 2.2.20, "Standards Plus"
* PMBOK Guide, 7th edition, page 67, section 2.2.21, "Glossary"
* PMBOK Guide, 7th edition, page 69, section 2.2.22, "References"
* PMBOK Guide, 7th edition, page 71, section 2.2.23, "Index"
* PMBOK Guide, 7th edition, page 73, section 2.2.24, "Appendix X1: Summary of Key Concepts"
* PMBOK Guide, 7th edition, page 75, section 2.2.25, "Appendix X2: Summary of Tailoring Considerations"
* PMBOK Guide, 7th edition, page 77, section 2.2.26, "Appendix X3: Summary of Tools and Techniques"
* PMBOK Guide, 7th edition, page 79, section 2.2.27, "Appendix X4: Summary of Agile, Iterative, Adaptive, and Hybrid Approaches"
* PMBOK Guide, 7th edition, page 81, section 2.2.28, "Appendix X5: Contributors and Reviewers"
* PMBOK Guide, 7th edition, page 83, section 2.2.29, "Appendix X6: PMI Code of Ethics and Professional Conduct"
* PMBOK Guide, 7th edition, page 85, section 2.2.30, "Appendix X7: Application Area Extensions"
* PMBOK Guide, 7th edition, page 87, section 2.2.31, "Appendix X8: Summary of Changes"
* PMBOK Guide, 7th edition, page 89, section 2.2.32, "Introduction"
* PMBOK Guide, 7th edition, page 91, section 2.2.33, "Performance Domain: Stakeholders"
* PMBOK Guide, 7th edition, page 93, section 2.2.34, "Performance Domain: Team"
* PMBOK Guide, 7th edition, page 95, section 2.2.35, "Performance Domain: Development Approach and Lifecycle"
* PMBOK Guide, 7th edition, page 97, section 2.2.36, "Performance Domain: Planning"
* PMBOK Guide, 7th edition, page 99, section 2.2.37, "Performance Domain: Project Work"
* PMBOK Guide, 7th edition, page 101, section 2.2.38, "Performance Domain: Delivery"
* PMBOK Guide, 7th edition, page 103, section 2.2.39, "Performance Domain: Measurement"
* PMBOK Guide, 7th edition, page 105, section 2.2.40, "Performance Domain: Uncertainty"
* PMBOK Guide, 7th edition, page 107, section 2.2.41, "Closing"
* PMBOK Guide, 7th edition, page 109, section 2.2.42, "Models, Methods, and Artifacts"