This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pharmacology
[{'content': 'Tolerance develops to following actions of Morphine except \nSelect and explain. \nA. Euphoria, B. Miosis, C. Nausea and vomiting, D. Analgesia', 'role': 'user'}, {'content': 'Answer: B \nExplanation: "Tolerance develops to almost all actions of morphine except the constipation and miotic action".', 'role': 'assistant'}]