Which VMware functionality allows migration of VMs between ESXi hosts with different CPU architectures?

Enhanced vMotion Compatibility (EVC) is the correct answer because it specifically addresses the need to maintain consistent CPU compatibility across different ESXi hosts within a cluster. EVC allows virtual machines to be migrated between hosts that have different CPU architectures or generations, ensuring that the VMs can run without compatibility issues due to differences in CPU features.

When EVC is enabled, it makes sure that the virtual machines use a compatible set of CPU features that all hosts in the cluster can support. This is particularly useful when updating hardware or when using a mix of hardware from different vendors or generations within the same cluster.

In contrast, vSphere Storage DRS focuses on optimizing the distribution of storage resources, while vSphere HA provides high availability for virtual machines by restarting them on other hosts in case of a failure. VMware Fault Tolerance offers continuous availability for VMs but does not facilitate CPU architecture differences during migration. Therefore, these functionalities do not address VM migrations between hosts with varying CPU architectures.