Which option describes the effect of using softphones instead of VoIP handsets on QoS implementation for the voice traffic?

A.
It provides a Layer 2 CoS marking in the frames that can be used for QoS implementation.

B.
Using softphones means that 802.1Q tagging must be configured between the PC and the switch

C.
The voice traffic of softphones is mixed with data traffic of PC on the access VLAN

D.
By using softphones, the implementation of a QoS depends only on trusting DSCP markings set by the PC.