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': 'Drug used to treat extrapyramidal syndrome due to phenothiazines: \nSelect and explain. \nA. Diphenhydramine, B. Benzhexol, C. Clonidine, D. Promethazine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]