What can call oversubscription cause if you do not have call admission control?

A.
Echo

B.
Call drop

C.
Talk back

D.
Voice packet loss

E.
Call processing delay

Explanation:
An additional contributor to packet loss in campus networks is TX buffer congestion. Transmit buffer congestion can happen if a rate change occurs or if many interfaces are aggregated into a single uplink, resulting in an oversubscription of the uplink’s capacity to buffer packets.
Page 3-2, Cisco AVVID Network Infrastructure Enterprise Quality of Service Design