What is the result of a “Consolidate” action on a virtual machine?
A.
All snapshots on the virtual machines will be deleted.
B.
The virtual machine will be reverted to its last snapshot.
C.
Redundant delta disks will be combined and deleted.
D.
A new snapshot with memory state will be created.
C is correct.
Source: https://docs.vmware.com/en/VMware-vSphere/6.5/com.vmware.vsphere.vm_admin.doc/GUID-2F4A6D8B-33FF-4C6B-9B02-C984D151F0D5.html
The presence of redundant delta disks can adversely affect virtual machine performance. You can combine such disks without violating a data dependency. After consolidation, redundant disks are removed, which improves virtual machine performance and saves storage space.