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
Which among the following NOT a pharmacological action of opioids 
Select and explain. 
A. Cough suppression, B. Anti-emesis, C. Miosis, D. Truncal rigidity
B: Anti-emesis
Answer: B: Anti-emesis 
Explanation: None