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: Unknown
[{'content': 'All of the statement about H1 anti histaminics are true except - \nSelect and explain. \nA. Tolerance may develop to some of its side effects, B. local application can be used for contact dermatitis, C. combination with an H,1 antagonist may control some cases of chronic urticaria, D. Many of them exhibit cholinergic effect', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans-D', 'role': 'assistant'}]