Which app should be targeted in a Conditional Access policy to exclude unmanaged devices from MFA?

The appropriate app to target in a Conditional Access policy for excluding unmanaged devices from multi-factor authentication (MFA) is Azure Windows VM Sign-In. This is because Conditional Access policies are utilized to manage how users authenticate to different applications and resources, particularly when considering the state of the devices being used.

By targeting Azure Windows VM Sign-In, you are effectively stating that this specific sign-in pathway is where unmanaged devices should not be prompted for MFA. Since Azure Windows VM Sign-In directly relates to the authentication process used to access Azure Virtual Machines, it is crucial for ensuring that users operating on unmanaged devices can have a distinct access experience aligned with security policies.

The other apps listed, while they are all part of the Azure ecosystem, do not specifically pertain to the scenario of excluding unmanaged devices from MFA in a parallel manner as Azure Windows VM Sign-In does. Each of the alternatives serves a different purpose and context, making them less suitable for this particular policy goal.