This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nervous System, Subject name: Physiology
[{'content': 'Which of the following is responsible for skeletal muscle relaxation? \nSelect and explain. \nA. Dystrophin, B. Tropomyosin, C. Myosin, D. Actin', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B TropomyosinRef: Gattong, 25th ed. pg. 101* Tropomyosin acts as a relaxing protein at rest by covering the sites where myosin binds to action* Dystrophin is a sarcolemmal protein providing calcium input to sarcoplasmic reticulum. This Ca++ is useful in coupling of actin-myosin complex.', 'role': 'assistant'}]