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
The nerve impulse which leads to initiation of muscle contraction ? 
Select and explain. 
A. 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
A: Causes opening of the calcium channels which leads to increase in calcium ion concentration with use of sarcomere
Answer: A: Causes opening of the calcium channels which leads to increase in calcium ion concentration with use of sarcomere 
Explanation: None