Which of the following is NOT a distinguishing feature between larger veins and arteries
A) Veins have valves whereas arteries do not have valves
B) The tunics in veins are not as clearly delimited as are the tunics in arteries
C) The walls in veins are thinner than the walls in arteries
D) The lumen of a vein is smaller than the lumen of an artery
E) None. All of the above are true