This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Opioids and Alcohols, Subject name: Pharmacology
[{'content': 'All of the following effects are produced by mu opioid receptor except ? \nSelect and explain. \nA. Tachycardia, B. Miosis, C. Sedation, D. Euphoria', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Effects of Mu opioid receptor activation results in S- Sedation A- Analgesia C- Constipation R- Respiratory depression U- eUphoria M- Miosis', 'role': 'assistant'}]