Explanation:

The correct answer is A. From PowerShell, run the Repair-AADCloudSyncToolsAccount cmdlet. This is the least administrative effort because the cmdlet is designed specifically to repair the synchronization service account used by Microsoft Entra synchronization services. Microsoft documents Repair- AADCloudSyncToolsAccount as a cmdlet that deletes the current sync account if present and then resets the sync account authentication by creating or using a new sync account in Microsoft Entra ID. That directly matches the error indicating an issue with the service account used for synchronization.
Microsoft's troubleshooting guidance also states that when you need to repair the cloud sync service account, you should run Connect-AADCloudSyncTools and then Repair-AADCloudSyncToolsAccount from an elevated PowerShell session, after which the account should be repaired successfully.
Set-ADSyncScheduler is wrong because it controls the synchronization schedule; it does not repair service account authentication. Resetting the ADSync service account password manually is risky because Microsoft warns that changing ADSync service account credentials after installation can cause the sync service to fail, lose database access, and stop synchronization until the original credentials are restored. Resetting the account from the Entra admin center is not the documented repair path.

Explanation:

See the solution below:
Explanation:
Add Lynne Robbins to the eDiscovery Manager subgroup of the built-in eDiscovery Manager role group. Do not add her as an eDiscovery Administrator because that would provide organization-wide access to all eDiscovery cases.
Step-by-Step Solution with Explanation:
* Sign in to the Microsoft Purview portal with an account assigned the Role Management role or membership in Organization Management .
* Select Settings .
* Navigate to:
Roles and scopes # Role groups
Some tenant interfaces display this directly as Settings # Role groups .
* On Role groups for Microsoft Purview solutions , search for:
eDiscovery Manager
* Select the eDiscovery Manager role group.
* Select Edit .
* On the Manage eDiscovery Manager page, select Choose users .
* Search for and select Lynne Robbins .
* Select Select , and then select Next .
* When the eDiscovery Administrator membership page appears, do not add Lynne. Continue by selecting Next .
* If administrative-unit scoping is presented, retain organization-wide or Full directory access unless the task environment specifies an administrative unit.
* Select Next # Save # Done .
* Reopen the role group and verify that Lynne appears under eDiscovery Managers , not eDiscovery Administrators .
An eDiscovery Manager can create and manage cases, run searches, manage holds, and access cases they create or to which they are assigned. An eDiscovery Administrator can access all cases, which exceeds this requirement. Microsoft: Assign permissions in eDiscovery

Reference:
https://support.microsoft.com/en-us/windows/which-version-of-windows-operating-system-am-i-running-628bec99-476a-2c13-5296-9dd081cdd808