What is a similarity between arteries and capillaries?

A. They both have elastic tissue.
B. They both have smooth muscle cells.
C. Neither has collagen fibres in their walls.
D. Neither has valves.

D

This question presented a different way of comparing blood vessels, since students often compare arteries and veins, rather than capillaries, so it was an indirect assessment of the structure of the three types of blood vessel. Many candidates picked options A or B, but overall the question discriminated well.