What should you recommend?

Your network contains an Active Directory domain.
The domain contains a site named Site1.

All of the client computers in Site1 use static IPv4 addresses on a single subnet.
Site1 contains a Storage Area Network (SAN) device and two servers named Server1 and Server2 that run Windows Server 2012.
You plan to implement a DHCP infrastructure that will contain Server1 and Server2.
The infrastructure will contain several IP address reservations.
You need to recommend a solution for the DHCP infrastructure to ensure that clients can receive IP addresses from a DHCP server if either Server1 or
Server2 fails.
What should you recommend? (Each correct answer is a complete solution. Choose all that apply.)

A.
Configure all of the client computers to use IPv6 addresses, and then configure Server1 and Server2 to run DHCP in stateless mode.

B.
Configure Server1 and Server2 as members of a failover cluster, and then configure DHCP as a clustered resource.

C.
Configure a DHCP failover relationship that contains Server1 and Server2.

D.
Create a scope for each server, and then configure each scope to contain half of the IP addresses.

Explanation:
// 30/11/2015 checked
certbase notes:
We can either use the Failover Clustering for the role DHCP server, the new DHCP failover or a shared address space configured to compensate for the failure of a
single DHCP server. A shared address space, however, does not support the proposed IP address reservations. In addition, the number of available IP addresses is
reduced if a server fails to half.