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
Antiemetic effect of Metoclopromide is mainly due to its action as 
Select and explain. 
A. 5HT3 antagonist, B. D2 antagonist, C. M3 antagonist, D. 5HT4 agonist
B: D2 antagonist
Answer: B: D2 antagonist 
Explanation: Antiemetic effect of Metoclopramide is because of D2 antagonism > 5HT3 antagonism.
Prokinetic effect is due to 5HT4 agonism.