[A] : Acetylchoiine allows a nerve cell to com- municate chemically with a muscle cell at neuromuscular junction.
[R]: Acetyicholine diffuses across the junc- tion and binds to some receptors on mem- brane of muscle cell.
A. If both A and R are true and R is the correct explanation of A
B. If both A and R are true but R is not the correct explanation of A
C. If A is true and R is false
D. If both A and R are false