What Are Three Largest Sources of Delay (Latency) in Message

Multiple Choice

What are three largest sources of delay (latency) in message transmissions?

A) propagation delay, delay at hosts, delay at intermediary devices
B) delay at hosts, delay at intermediary devices, delay due to packet collisions
C) delay of user response, delay at intermediary devices, propagation delay
D) delay of user response, delay at intermediary devices, delay due to packet collisions
E) propagation delay, delay at hosts, delay due to packet collisions