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: Anaesthesia
Most potent antiemetic agent used in preoperative period – 
Select and explain. 
A. Glycopyrolate, B. Hyoscine, C. Atropine, D. Metochlorpromide
B: Hyoscine
Answer: B: Hyoscine 
Explanation: Commonly used antiemetics in pre-operative period are Hyoscine, Ondansetron, Perinorm.

Amongst this Hyoscine is most potent :-
"Hyoscine is the most potent antiemetic to be used as part of premedication".      
— Fundamental of anaesthesia