This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Rheumatic Heart Disease, Subject name: Pediatrics
[{'content': 'Least common valve involved in rheumatic fever- \nSelect and explain. \nA. Aortic valve, B. Tricuspid valve, C. Mitral valve, D. Pulmonary valve', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., Pulmonary valve Endocarditis in rneumatic feverMitral valve involved almost all the cases of Acute Rheumatic Fever.Almost 25% of MR is asociated with aortic regargitation.Tricuspid regurgitation is seen in 10-30% cases.Pulmonary valve involvement is never seen.", 'role': 'assistant'}]