A 32-year-old woman presents to clinic with progressive dyspnea on exertion and fatigue over the past 2 years. She has a history of acute rheumatic fever at age 8 and reports being told she had a heart murmur as a child but has not had cardiac follow-up in over a decade. On physical examination, her vital signs are: BP 118/76 mmHg, HR 88 bpm, RR 18, O2 sat 96% on room air. Cardiac auscultation reveals a loud S1, an opening snap in early diastole, and a low-pitched, rumbling diastolic murmur best heard at the apex with the patient in the left lateral decubitus position. The murmur does not radiate to the axilla. Transthoracic echocardiography demonstrates a mitral valve area of 1.2 cm² (normal >4 cm²), severe left atrial enlargement, and normal left ventricular systolic function. Which of the following best explains the hemodynamic abnormality responsible for this patient's symptoms?

1. A)Increased left ventricular afterload due to rheumatic aortic stenosis
2. B)Impaired left ventricular systolic contractility from chronic pressure overload
3. C)Obstruction to passive left ventricular filling during early diastoleGABARITO
4. D)Acute mitral regurgitation resulting in pulmonary edema
5. E)Rupture of the anterior mitral leaflet with flail segment formation