You need to recommend changes to the DHCP infrastructure to ensure that the client computers continue to receive IP addressing information if a single DHCP server fails

Your network contains a server named Server1 that runs Windows Server 2012. Server1 has the DHCP
Server server role installed.
All of the client computers that are in a subnet named Subnet1 receive their IP address configurations
from Server1.
You plan to add another DHCP server named Server2 to Subnet1.
You need to recommend changes to the DHCP infrastructure to ensure that the client computers
continue to receive IP addressing information if a single DHCP server fails.
What should you do?
More than one answer choice may achieve the goal. Select the BEST answer.

A.
Create a Network Load Balancing (NLB) cluster.

B.
Configure Failover for the scope.

C.
Create a DHCP failover cluster.

D.
Create a split scope.

Explanation:
One of the great features in Windows Server 2012 R2 is the DHCP failover for Microsoft DHCP scopes.
Failover is where the environment suffers an outage of a service which triggers the failover of thatservice function to a secondary server or site. The assumption for most failover configurations is that the
primary server is completely unavailable.

Step-by-Step: Configure DHCP for Failover
https://technet.microsoft.com/en-us/library/hh831385.aspx