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
Antihistamines used in motion sickness is 
Select and explain. 
A. Cetrizine, B. Meclizine, C. Diphenhydramine, D. Fexofenadine
C: Diphenhydramine
Answer: C: Diphenhydramine 
Explanation: Diphenhydramine and promethazine have maximum anti cholinergic activity and maximum ability to cross the blood brain barrier and are thus most effective in motion sickness . Refer katzung 11/e p278