Which of the following statements regarding arteries and veins is true?

A major difference between the arterial and venous systems is that 

(a) Arteries are usually more superficial than veins.

(b) In the limbs there is dual venous drainage.

(c) Veins are usually less branched compared to arteries.

(d) Veins exhibit a much more orderly pattern of branching in the limbs.

(e) Veins are not found in the abdominal cavity.

Which of the following can lead to decreased venous return of blood to the heart?

a. An increase in blood volume

b. An increase in venous pressure

c. Damage to the venous valves

d. Increased muscular activity

A major difference between venules and arterioles is that:

Which of the following is not a reason that veins need valves to prevent backflow, but arteries do not?