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
[{'content': 'Antihistamines used in motion sickness is \nSelect and explain. \nA. Cetrizine, B. Meclizine, C. Diphenhydramine, D. Fexofenadine', 'role': 'user'}, {'content': 'Answer: C \nExplanation: 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', 'role': 'assistant'}]