Jitter is causing problems with the VOIP application in the Company network. 
What causes  network jitter？（）

A.The trunk port Fa0/1 on switch A_SW will trust allCoS values on the frames coming from the IP  phone.
B.The trunk port Fa0/1 on switch A_SW will trust allCoS values on the frames received on the IP  phone.
C.The trunk port Fa0/1 on switch D_SW will trust allCoS values on the frames coming from port  Fa0/1 on A_SW.
D.The trunk port Fa0/1 on switch D_SW will trust allCoS values on the frames received on the  A_SW switch port Fa0/4.
E.The trunk port Fa0/1 on switch D_SW will trust allCoS values on the frames received on the IP  phone port.

A.The voice traffic cannot be forwarded to the distribution layer.
B.The voice traffic cannot use 802.1p priority tagging.
C.Port security cannot be enabled on the switch that is attached to the IP phone.
D.Quality of service cannot be applied for the voice traffic.

A.DSCP map needs to be configured for VOIP.
B.ToS has not been configured.
C.ToS has been misconfigured.
D.The command mls qos needs to be turned on in global configuration mode.
E.There is not a Cisco Phone attached to the interface.