A 28-year-old woman with exertional dyspnea has a loud, tapping first heart sound best heard at the apex. ECG shows normal PR interval. Which pathological feature best explains this auscultatory finding?
A
Calcified immobile mitral valve leaflets
B
Forceful ventricular contraction due to hypertrophy
C
Wide separation of M1 and T1
D
Mobile mitral valve leaflets with delayed closure