A 31-year-old woman presents to the clinic with shortness of breath, palpitations, and fatigue. She has had these symptoms over the last several weeks. She had been tolerating these symptoms until last night when she could not fall asleep due to palpitations. She has a past medical history of infective endocarditis 6 months ago that was successfully treated with antibiotics. She does not smoke or drink alcohol. Her blood pressure is 138/89 mm Hg and her pulse is 76/min and regular. The cardiac exam reveals a soft S1, S3 gallop, a hyperdynamic apex beat, and a pansystolic murmur that radiates to the axilla on auscultation. Echocardiography reveals incompetence of one of the valves. Which of the following sites is the best position to auscultate this defect?
A. Right lower end of the body of the sternum
B. 4th intercostal space at the midclavicular line on the left side
C. Medial end of the 2nd intercostal space on the right side
D. 5th intercostal space at the midclavicular line on the left side
E. Medial end of the 2nd intercostal space on the left side