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
Dry mouth during antidepressant therapy is caused by blockade of - 
Select and explain. 
A. Muscarinic acetylcholine receptors, B. Serotonergic receptors, C. Dopaminergic receptors, D. GABA receptors
A: Muscarinic acetylcholine receptors
Answer: A: Muscarinic acetylcholine receptors 
Explanation: Ans. is 'a' i.e., Muscarinic acetylcholine receptors "Blurred vision, dry mouth, urinary hesitancy or retention, and constipation represent the most common antimuscarinic complaints".