Answer
c.
Work Step by Step
The first sound of the heartbeat that is heard is "lub," which is the sound that is made when blood tries to rush back into the atria from the ventricles and hits against the atrioventricular (AV) valves. The following sound, "dup," is the sound made when blood tries to rush back into the ventricles from the arteries and hits against the semilunar valves.
In this problem, the first sound heard from Janet's heart is absolutely normal, which means the AV valves are functioning correctly. The second sound, the hiss that is heard, means that the semilunar valves are not functioning correctly and are allowing blood to leak back into the ventricles from the arteries.
