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
Mechanism of action of buspirone is? 
Select and explain. 
A. 5 HT1A paial agonism., B. 5 HT1B antagonism., C. 5 HT1B paial agonism., D. 5 HT2C antagonism.
A: 5 HT1A paial agonism.
Answer: A: 5 HT1A paial agonism. 
Explanation: Ans. A. HT1A paial agonism5 HT1A:Presynaptic autoreceptor.Modulates serotonin release.Paial 5 HT1A agonists:Buspirone, isapirone, gepirone.Useful as anti-anxiety drug.