You have an on-premises AD DS domain with five domain-joined Windows Server machines and two Windows Server machines in a workgroup. To create a connection security rule between the domain-member servers and the workgroup servers, which authentication method should you select?

Computer certificate is the correct authentication method because it allows secure communication between machines that are not part of the same Active Directory domain, such as domain-joined servers and workgroup servers. Kerberos V5 (both User and Computer) relies on Active Directory for authentication, which is not available for workgroup machines. NTLMv2 is a legacy authentication protocol and is generally less secure and not recommended for new deployments, especially when certificates offer a more robust solution for cross-domain or workgroup scenarios.