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': 'Which of the following is involved in peristalsis by causing relaxation ? \nSelect and explain. \nA. Substance P, B. Acetylcholine, C. VIP, D. Norepinephrine', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., VIP In peristlasis :- Acetylcholine & substance P - Causing smooth muscle contraction. VIP, NO & ATP - Producing relaxation ahead of stimulus.", 'role': 'assistant'}]