Exhibit:
PC1 sends a packet to R1. R1 forwards to R2, then R3, and finally R3 forwards the packet to the destination, PC2. R1 marks the packet with IP Precedence 3.
Which statement is true?
A.
When classifying packets at Layer 3, only Layer 3 IP Precedence marking can be used.
B.
R2 and R3 can perform QoS features that ignore the marked IP Precedence field in the packet.
C.
R2 and R3 can only perform QoS features based on the IP Precedence field, since the packet had already been marked.
D.
R2 can apply QoS features to the packet, and R3 can on ingress, but R3 cannot apply QoS features to the packet as it exists the Ethernet port on which PC2 resides.