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: Pharmacology
Opioid tolerance develops to all of the following actions, except: 
Select and explain. 
A. Miosis, B. Analgesia, C. Euphoria, D. Nausea and vomiting
A: Miosis
Answer: A: Miosis 
Explanation: Ans. is 'a' i.e., Wasis Tolerance is exhibited to most actions of morphine except for miosis and constipation.