A 47-year-old female with rheumatic fever history presents with dyspnea on exertion. Vital signs show BP 128/76 mmHg, HR 92/min, RR 18/min, temp 37.2°C, SpO2 98% on room air. Cardiac examination reveals a low-pitched, rumbling diastolic murmur preceded by an opening snap. Chest X-ray shows mild left atrial enlargement. No peripheral edema noted. She takes no cardiac medications. At which anatomical location is this murmur best appreciated?

1. A)Right second intercostal space
2. B)Left lower sternal body border
3. C)Left second intercostal space
4. D)Right fifth intercostal space
5. E)Left fifth intercostal spaceGABARITO