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
[{'content': 'Antihistaminic used in motion sickness is : \nSelect and explain. \nA. Cetirizine, 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.', 'role': 'assistant'}]