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: Physiology
[{'content': 'Muscle hypotension is caused by? \nSelect and explain. \nA. Bradykinin, B. Actin, C. Myosin, D. Relaxin', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is'a'i.e., BradykininOnly bradykinin cause hypotension - Local hypotension in skeletal muscle (If pressure BP to fall below 50 mm Hg).", 'role': 'assistant'}]