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': 'The nerve impulse which leads to initiation of muscle contraction ? \nSelect and explain. \nA. Causes opening of the calcium channels which leads to increase in calcium ion concentration with use of sarcomere, B. Causes both the plasma membrane and the T tubules to undergo hyperpolarization, C. Inhibits Sodium entry in sarcomere, D. Is inhibited by binding of acetylcholine to receptors in the sarcoplasmic reticulum', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]