Which of the following factors assists in the return of venous blood to the heart? (1) Arterial dilation (2) Valves in the veins (3) Sympathetic stimulation (4) Compression of veins by muscular movements Select one: a. 1, 2, 3 b. 1, 2, 3, 4 c. 1, 3, 4 d. 1 and 2 e. 2, 3, 4