What is the purpose of VPLEX Witness in a Metro environment?

A.
Observe the state of the clusters, Distinguish link outages, Intercluster failures, Resume or suspend I/O

B.
Prevent cluster link failure, Stop I/O transfer, Split consistency groups, Failover consistency groups

C.
Send notifications, Pause I/O transfer, Initiate vault dump, Failover consistency groups

D.
Observe state of the clusters, Suspend I/O, Execute health-check, Resume I/O