Why Is the Change in Sound Made by a Passing

Question 7
Multiple Choice

Why is the change in sound made by a passing train's whistle similar to the reason the pitch rises quickly in systole and drops quickly in early diastole when measuring arterial sounds? A)Both are explained by B-mode ultrasonography. B)Both involve the science of plethysmography. C)Both are explained by the Doppler effect. D)Both are explained by the science of atomic behavior in a strong magnetic field such as MRI.