Your network contains an Active Directory domain named contoso.local. All users have email addresses in the
@contoso.com domain.
You need to ensure that users can register Windows 10 mobile devices for mobile device management (MDM).
Which DNS record should you create?

A.
Enterpriseregistration.adatum.com

B.
Deviceregistration.adatum.com

C.
Deviceregistration.contoso.com

D.
Enterpriseregistration.contoso.com

Explanation:
https://technet.microsoft.com/en-us/windows/dn771709.aspx