When Auscultating Heart Sounds, the Patient Is Asked to Lie

When auscultating heart sounds, the patient is asked to lie on the left side, then sit up and lean forward. What is the rationale for this action?

A) The heart is closer to the chest wall.
B) It diminishes the effect of respiratory sounds during auscultation.
C) Use of the stethoscope diaphragm improves auscultation of high pitched murmurs.
D) Use of the bell side of the stethoscope allows low pitched sounds to be readily identified.