Regarding the following statements about packet loss in QoS, which is wrong?

Regarding the following statements about packet loss in QoS, which is wrong?
A . When the router receives a data packet, it may be unable to process the data packet because the CPU is busy, resulting in packet loss.
B . When data packets are scheduled to the queue, packet loss may occur because the queue is full.
C . When data packets are transmitted on the link, they may be lost due to link failures and other reasons.
D . Packet loss is generally caused by delay. When the queue is full, tail drop is generally used to drop packets.

Answer: D