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': 'What is the counterpart of troponin in smooth muscles \nSelect and explain. \nA. Nebulin, B. Calsequestrin, C. Calmodulin, D. Titin', 'role': 'user'}, {'content': 'Answer: C \nExplanation: In skeletal muscle Ca2+\xa0binds to Troponin-C. Likewise, in smooth muscle Ca2+\xa0binds to Calmodulin and activates myosin light chain Kinase.', 'role': 'assistant'}]