Which user can sign in to Azure AD?

Your network contains an on-premises Active Directory domain that sync to an Azure Active Directory (Azure AD) tenant.

The tenant contains the shown in the following table.

All the users work remotely.

Azure AD Connect is configured in Azure as shown in the following exhibit.

Connectivity from the on-premises domain to the internet is lost.

Which user can sign in to Azure AD?
A . User1 only
B . User1 and User 3 only
C . User1, and User2 only
D . User1, User2, and User3

Answer: A