A 42-year-old woman presents to the emergency department with progressive dyspnea, orthopnea, and nocturnal cough for 3 weeks. She reports a history of acute rheumatic fever at age 12 that was treated with antibiotics but no long-term penicillin prophylaxis was given. Vital signs: BP 128/76 mmHg, HR 108 bpm, RR 24/min, SpO2 87% on room air. On cardiac examination, a high-pitched, low-pitched rumbling diastolic murmur is heard best at the apex with the patient in the left lateral decubitus position. Bilateral crackles are present at lung bases. Chest X-ray shows pulmonary edema and straightening of the left heart border. Echocardiography reveals a mitral valve area of 1.1 cm² with a peak transmitral gradient of 18 mmHg. Which of the following best explains the pathophysiology of this patient's current clinical presentation?

1. A)Chronic aortic regurgitation leading to volume overload and eccentric left ventricular hypertrophy
2. B)Acute bacterial endocarditis with vegetation-induced tricuspid regurgitation
3. C)Mitral stenosis causing impaired left ventricular filling and pulmonary venous congestionGABARITO
4. D)Pulmonary hypertension from chronic left-to-right shunting through an atrial septal defect
5. E)Aortic stenosis with preserved ejection fraction causing diastolic dysfunction