Which of the listed resources can be assigned the Contributor role for VM1?

The Contributor role can be assigned to Managed Identities and Azure Active Directory (Azure AD) users, groups, or service principals. In this scenario, Managed1 is a Managed Identity and App1 is an Azure AD application (which has an associated service principal). Therefore, both Managed1 and App1 can be assigned the Contributor role for VM1. Group1 is an Azure AD group, which can also be assigned roles, but it was not listed as a correct option in combination with App1. VM1 itself is the resource being acted upon, not an identity that can be assigned a role. VM2 is another virtual machine and not an identity that can be assigned a role on VM1.