This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Muscle Physiology, Subject name: Physiology
[{'content': 'The nerve impulse which leads to initiation of smooth muscle contraction \nSelect and explain. \nA. Cause opening of the calcium channel which leads to increase in Ca+2 contraction, B. Cause both plasma membrane and T - tubules to undergo depolarisation, C. Inhibits Na+ entry in sarcomere, D. Is initiated by binding of acetylcholine to receptors in sarcoplasmic reticulum', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) Cause opening of the calcium channel which leads to increase in Ca2+ contraction(Ref: Ganong, 25th ed/p.116)The never impulse which leads to initiation of smooth muscle contraction Cause opening of the calcium channel which leads to increase in Ca2+ contraction', 'role': 'assistant'}]