Which of the following is correct about the transverse section of a vein, when compared with that of an artery?

A. The lumen of a vein is wider than that of an artery
B. The endothelium of the vein is thinner than that of an artery
C. There are more smooth muscles in a vein than in an artery
D. There are valves in veins but not in arteries.

Correct Answer:

Option D – There are valves in veins but not in arteries.