In an Active Directory Domain Services (AD DS) environment, the PDC Emulator (Primary Domain Controller Emulator) operations master role is responsible for acting as the authoritative time source for the domain. All other domain controllers synchronize their clocks with the PDC Emulator. Therefore, to configure DC3 as the authoritative time server, you must transfer the PDC Emulator role to it.

The PDC Emulator role is a domain-level Flexible Single Master Operation (FSMO) role. It is managed and transferred using the Active Directory Users and Computers console. You would right-click the domain object within this console, select "Operations Masters," and initiate the transfer under the PDC tab.

Microsoft Learn. (2024). FSMO placement and optimization on Active Directory domain controllers. Retrieved from https://learn.microsoft.com/en-us/troubleshoot/windows-server/identity/fsmo-placement-and-optimization-on-ad-dcs (Section: "PDC emulator")

Microsoft Learn. (2023). How to configure an authoritative time server in Windows Server. Retrieved from https://learn.microsoft.com/en-us/troubleshoot/windows-server/identity/configure-authoritative-time-server

Microsoft Learn. (2024). View and transfer FSMO roles. Retrieved from https://learn.microsoft.com/en-us/troubleshoot/windows-server/identity/view-transfer-fsmo-roles (Table: "FSMO roles and the snap-ins to manage them")