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': 'Double apical impulse: March 2013 \nSelect and explain. \nA. MR, B. AR, C. AS, D. MS', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. C i.e. AS Aoic stenosis Features: - Sustained heaving apex, - Angina, - Sudden death Degenerative calcification is a cause of AS Exercise testing is C/ I in AS', 'role': 'assistant'}]