This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Central Nervous system, Subject name: Pharmacology
[{'content': 'Dryness of mouth caused by antipsychotic drug is caused by blockade of: \nSelect and explain. \nA. Muscarinic ACh receptors, B. GABA receptors, C. Serotonergic receptors, D. Dopaminergic receptors', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Xerostomia, commonly known as "dry mouth," is a repoed side effect of >1,800 drugs from >80 classes. ... Among all repoed side effects of antidepressants andantipsychotics, dry mouth often is the most prevalent complaint. For example, in a study of 5 antidepressants 35% to 46% of patients repoed dry mouth. Ref KD Tripati 8th ed.', 'role': 'assistant'}]