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': 'A continuous murmur is heard in all of the following conditions except: \nSelect and explain. \nA. Ventricular septal defect with aoic regurgitation, B. Patent ductus aeriosus, C. Coronary aeriovenous fistula, D. Venous hum', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Answer is A (Ventricular septal defect with Aoic Regurgitation) Ventricular septal defect with Aoic Regurgitation does not produce a continuous murmur Patent Ductus Aeriosus produces a continuous murmur by the presence of a high to low pressure shunt Coronary AV fistula also produces a continuous murmur by the presence of a high to low pressure shunt Venous hum produces a continues murmur by rapid flow of blood Venous hum is a continues murmur usually audible over the medial aspect of the right supraclavicular fossa with the patient upright (Harrison)', 'role': 'assistant'}]