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
[{'content': 'Ejection click is heard in: \nSelect and explain. \nA. Early systole, B. Late systole, C. Early diastole, D. Late diastole', 'role': 'user'}, {'content': "Answer: A \nExplanation: The ejection sound is a sharp, high-pitched event occurring in early systole and closely following the first hea sound. Ejection sounds occur in the presence of semilunar valve stenosis and in conditions associated with dilation of the aoa or pulmonary aery. Ref: Harrison's principle of internal medicine 17th edition, chapter 220.", 'role': 'assistant'}]