This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Autacoids, Subject name: Pharmacology
Mechanism of action of cisapride? 
Select and explain. 
A. Inhibition of D2 receptors, B. Antagonism of 5HT3 receptors, C. Antagonism of 5HT4 receptors, D. Agonism of 5HT4 receptors
D: Agonism of 5HT4 receptors
Answer: D: Agonism of 5HT4 receptors 
Explanation: Cisapride, mosapride, and renzapride are prokinetic agents acting by 5HT4 agonismRef: HL Sharma 3rd ed.Pg 355.