Action potential propagation in a skeletal muscle fiber ceases when acetylcholine is removed from the synaptic cleft. Which of the following mechanisms ensures a rapid and efficient removal of acetylcholine?a) Acetylcholine is degraded by acetylcholinesterase.b) Acetylcholine is transported back into the axon terminal by a reuptake mechanism.c) Acetylcholine is transported into the postsynaptic neuron by receptor-mediated endocytosis.d) Acetylcholine diffuses away from the cleft.