You have an on-premises Active Directory domain and a Microsoft Azure Active Directory. You have a
Microsoft Intune subscription that is linked to the Azure Active Directory.
You configure directory synchronization between the on-premises Active Directory and the Azure Active
Directory. You import 100 users into the Azure Active Directory.
Users report that they are unable to sigh in to Microsoft Intune. You confirm that each user has a valid Active
Directory account and password.
You open the Microsoft Intune Console and see the configuration of User1 as shown in the exhibit. (Click the
Exhibit button.)

You need to ensure that the users can sign in to Microsoft Intune.What should you do first?

A.
Activate the synchronized user accounts.

B.
Purchase an Enterprise Mobility Suite subscription.

C.
Configure Microsoft Intune for single sign-on.

D.
Create a new Security Group in Microsoft Intune named Domain Intune Users.

Explanation:
http://www.robinhobo.com/how-to-setup-microsoft-intune/