This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
A 20-year-old man comes to the physician for routine examination. He is afebrile and has clear breath sounds throughout. Cardiac examination shows a mid to late diastolic murmur on auscultation, loudest at the cardiac apex. 
Which of the following is the most likely cause for this patient’s murmur? 
Select and explain. 
A. Acute pericarditis, B. Congenital heart defect, C. Infective endocarditis, D. Rheumatic fever
D: Rheumatic fever
Answer: D: Rheumatic fever 
Explanation: None