Select all the correct answers.

Alfred has a golden retriever named Max. Max can recognize people from their smell. Max starts to bark and wag his tail when Alfred reaches the gate of his house, even though Max is 50 yards away in his kennel. What are the reasons for Max's ability to smell so well?

A. Dogs have more olfactory receptors in their noses, allowing them to identify people by their smell.
B. Dogs have highly sensitive olfactory receptors, allowing them to distinguish a person's unique odor.
C. Dogs have better eyesight than humans, allowing them to see faraway objects.
D. Dogs have an extended nervous system, allowing them to detect even the slightest movement in humans.
E. Dogs have connected optic and olfactory systems, allowing them such precision in smell.