This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: A.N.S., Subject name: Pharmacology
[{'content': 'Cholinomimetic is contraindicated in: \nSelect and explain. \nA. Glaucoma, B. Myasthenia gravis, C. Postoperative ileus, D. Partial heart block', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. D. Partial heart blocka. Cholinergic system has Inhibitory effect on heart mediated by M2 receptors.b. Cholinomimetics can convert a partial heart block into a complete heart block due to negative chronotropic,c. Dromotropic properties.', 'role': 'assistant'}]