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
Tolerance develops to following actions of Morphine except 
Select and explain. 
A. Euphoria, B. Miosis, C. Nausea and vomiting, D. Analgesia
B: Miosis
Answer: B: Miosis 
Explanation: "Tolerance develops to almost all actions of morphine except the constipation and miotic action".