This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thorax, Subject name: Anatomy
[{'content': 'A 35-year-old woman is admitted to the hospital with dyspnea. During physical examination her S1 heart sound is very loud. Which of the following valves is most likely defective? \nSelect and explain. \nA. Mitral valve, B. Aortic, C. Pulmonary, D. Aortic and pulmonary', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The mitral valve corresponds to the S1 heart sound produced during systole. The aortic and pulmonary valves correspond to the S2 heart sound produced during diastole. The tricuspid valve also corresponds with the S1 heart sound. The aortic valve, however, corresponds with the S2 sound, so this answer would be incorrect.', 'role': 'assistant'}]