Vault1 must allow access only from VM1, which is connected to VNet1. In Vault1's Networking settings, which action restricts access to only VM1?

To restrict access to Vault1 from only VM1, you must specify VM1's public IP address in the Firewalls and virtual networks settings. This creates an IP-based firewall rule, allowing traffic only from that specific IP. Adding a private endpoint for VM1 would allow access over a private network, but it doesn't restrict access only to VM1; other resources on the same VNet could potentially access it. Adding VNet1 would allow all resources within VNet1 to access Vault1, not just VM1. Allowing trusted Microsoft services bypasses the firewall for specific Azure services, which is not relevant for restricting access to a single VM.