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 acting on H2 receptors - 
Select and explain. 
A. Promethazine, B. Metoclopramide, C. Ondansetron, D. Amiodarone
A: Promethazine
Answer: A: Promethazine 
Explanation: Ans. is 'a' i.e., Promethazine Promethazine is an antihistaminic antiemetic.