Explanation:

Box 1: Yes
User1 is member of Group1.
User1 has MFA registered method of Microsoft Authenticater app (push notification) The Microsoft Authenticator authentication method policy is configured for Group1, registration is optional, authentication method is any.
Note: Microsoft Authenticator can be used to sign in to any Microsoft Entra ID account without using a password. Microsoft Authenticator uses key-based authentication to enable a user credential that is tied to a device, where the device uses a PIN or biometric. Windows Hello for Business uses a similar technology.
This authentication technology can be used on any device platform, including mobile. This technology can also be used with any app or website that integrates with Microsoft Authentication Libraries.
Box 2: No
User2 is member of Group2.
The Microsoft Authenticator authentication method policy is configured for Group1, not for Group2.
Box 3: No
User3 is member of Group1.
User3 has no MFA method registered.
User3 must choose an authentication method.
Note: Enable passwordless phone sign-in authentication methods
Microsoft Entra ID lets you choose which authentication methods can be used during the sign-in process.
Users then register for the methods they ' d like to use.
Reference:
https://learn.microsoft.com/en-us/azure/active-directory/authentication/howto-authentication-passwordless- phone

Reference:
https://docs.microsoft.com/en-us/mem/intune/protect/advanced-threat-protection-configure

Explanation:
User objects
User2 only
Microsoft 365 groups
User1, User2, and User3
User2 only can create user objects because User2 has the User Administrator role. Microsoft's Microsoft Entra built-in role reference states that the User Administrator role includes the permission to create users and manage users. The Groups Administrator role is scoped to group management, not user object creation.
The Teams Administrator role manages the Teams workload and does not grant general Microsoft Entra user creation rights.
For Microsoft 365 groups, the correct selection is User1, User2, and User3 . Microsoft states that the Groups Administrator role can create and manage groups across workloads, including Teams, SharePoint, Yammer, and Outlook, so User1 qualifies. The User Administrator role includes the ability to create and manage all groups , so User2 qualifies. The Teams Administrator role also explicitly grants the ability to create and manage all Microsoft 365 groups , because Teams administration depends on Microsoft 365 group-backed teams.
Therefore, choose User2 only for user objects and User1, User2, and User3 for Microsoft 365 groups.

Reference:
https://docs.microsoft.com/en-us/azure/active-directory/hybrid/choose-ad-authn

Reference:
https://docs.microsoft.com/en-us/mem/analytics/overview