When planning an upgrade for the Cisco Unified Contact Center Enterprise solution, what is the
proper order for upgrading the solution components?

A.
Upgrade the Cisco Unified Communications Manager cluster.
Upgrade the Cisco Unified Communications Manager Peripheral Gateways.
Upgrade the Administration and Data servers.
Upgrade the Call Router and Logger servers.

B.
Upgrade the Cisco Unified Communications Manager Peripheral Gateways.
Upgrade the Cisco Unified Communications Manager cluster.
Upgrade the Call Router and Logger servers.
Upgrade the Administration and Data servers.

C.
Upgrade the Call Router and Logger servers.
Upgrade the Administration and Data servers.
Upgrade the Cisco Unified Communications Manager Peripheral Gateways.
Upgrade the Cisco Unified Communications Manager cluster.

D.
Upgrade the Administration and Data servers.
Upgrade the Call Router and Logger servers.
Upgrade the Cisco Unified Communications Manager cluster.
Upgrade the Cisco Unified Communications Manager Peripheral Gateways.