You are answering a USMLE-style medical question. Question: A 47-year-old executive schedules an appointment his physician for a routine medical check-up. He currently has no complaints and claims to be “as fit as a fiddle.” The physical examination findings are unremarkable, except for a mid-systolic murmur heard in the 2nd left intercostal space that radiates to the carotids on auscultation. The physician instructs the patient to stand from a supine position with the stethoscope still placed on his chest. Which of the following changes would occur with this maneuver? Options: A) An increase in right atrial pressure B) An increase in pulmonary capillary wedge pressure C) A reduction in the slope of the pacemaker potential D) A reduction in diastolic filling time Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.