You have an Azure subscription with four virtual machines. You need the VMs to share a single identity whose credentials are managed automatically and to which privileges can be assigned. Which type of identity should you use?

A user-assigned managed identity is the correct choice because it allows multiple Azure resources, such as virtual machines, to share a single identity. This identity's credentials are automatically managed by Azure, eliminating the need for manual credential rotation or storage. You can then assign specific privileges to this shared identity, granting the VMs access to other Azure services without embedding secrets in your code or configuration. System-assigned managed identities are tied to a single resource's lifecycle and cannot be shared among multiple VMs. Service principals are application identities but require manual credential management (client secrets or certificates). User accounts are for human interaction and are not suitable for programmatic access by Azure resources.