During a normal call flow in the Cisco Unified Contact Center Enterprise solution, how long is the
agent phone engaged?

A.
from the point that the agent answers to the point that the agent is ready

B.
from the transfer to IVR to the point that the agent hangs up

C.
from the call arrival to the point that the agent hangs up

D.
from the point that the agent answers to the point that the agent hangs up