At a Capillary Bed, a Vasoconstrictor

Multiple Choice

At a capillary bed, a vasoconstrictor

A) constricts local arterioles, thereby increasing pressure and increasing local blood flow.
B) stimulates precapillary sphincters and decreases local blood flow.
C) dilates local arterioles, thereby increasing pressure and increasing local blood flow.
D) inhibits precapillary sphincters to relax and decreases local blood flow.
E) constricts precapillary sphincters and thereby increases local blood flow.