You need to ensure that the client computers can obtain IPv4 addresses from DC2

Your network contains an Active Directory domain named contoso.com. The domain contains a
domain controller named DC2 that runs Windows Server 2012 R2. DC2 has the DHCP Server server
role installed.
DHCP is configured as shown in the exhibit. (Click the Exhibit button.)

You discover that client computers cannot obtain IPv4 addresses from DC2.
You need to ensure that the client computers can obtain IPv4 addresses from DC2.
What should you do?

A.
Disable the Deny filters.

B.
Enable the Allow filters.

C.
Authorize DC2.

D.
Restart the DHCP Server service

Explanation:
From the exhibit we see a red marker on the IPv4 server icon. The DHCP server is not authorized.
Authorize DHCP Server
The final step is to authorize the server.
Right-click your FQDN and select Authorize.
Refresh the view by right-clicking your FQDN and selecting Refresh.
You should now see green check mark next to IPv4.

Example: Server 2012 DHCP Server Role