This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anatomy & Physiology (Oesophagus), Subject name: Surgery
[{'content': 'Lower esophageal sphincter tone is due to \nSelect and explain. \nA. Vasoactive intestinal peptide, B. Nitrous oxide, C. Acetylcholine, D. Pancreatic polypeptide', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. (c) AcetylcholineRef: Bailey & Love 26th ed. / 988There are two types of control of LES via the Myenteric plexus:* Excitatory (cholinergic) ganglionic neurons* Inhibitory (nitric oxide) ganglionic neuronsFunctionally, inhibitory neurons mediate Deglutitive lower esophageal sphincter (LES) relaxation and the sequential propagation of peristalsis.', 'role': 'assistant'}]