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 of the following does not exert an analgesic effect? 
Select and explain. 
A. Cholinergic antagonists, B. Adrenergic antagonists, C. Morphine, D. Substance P antagonists
A: Cholinergic antagonists
Answer: A: Cholinergic antagonists 
Explanation: None