An administrator has a mixture of Intel-based ESX Hosts in a DRS cluster where the CPUs are compatible in every way except that some support the NX/XD feature and some do not. What can you do to minimize the effect of these differences (Choose Two)?

A.
Mask the NX/XD bit in the Processor section of the Configuration tab on the ESX Hosts

B.
Mask the NX/XD bit on every virtual machine in the cluster

C.
Enable Rapid Virtualization Indexing

D.
Enable enhanced VMotion compatibility

Explanation:
vSphere Basic System Administration vCenter Server 4.0 ESX 4.0 ESXi 4.0, page 153.

Select Advanced > CPUID Mask.

1. Specify whether you want to hide the host’s CPU NX flag from the guest operating system

Hiding the NX flag prevents the guest operating system from making use of this CPU feature, but enables the virtual machine to be moved to hosts that do not include the NX feature. When the NX flag is visible, the guest operating system can make use of the feature, but the virtual machine can be moved only to hosts with the NX capability.

Enhanced VMotion Compatibility (EVC) processor support

Enhanced VMotion Compatibility (EVC) simplifies VMotion compatibility issues across CPU generations. EVC automatically configures server CPUs with Intel FlexMigration or AMD-V Extended Migration technologies to be compatible with older servers. After EVC is enabled for a cluster in the VirtualCenter inventory, all hosts in that cluster are configured to present identical CPU features and ensure CPU compatibility for VMotion. The features presented by each host are determined by selecting a predefined EVC baseline.