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': 'Effects mediated by H1 histamine receptor include : \nSelect and explain. \nA. Inhibition of gastric acid secretion, B. Induction of hepatic cytochrome P450 enzymes, C. Maintenance of a wakeful state, D. Vasoconstriction of arterioles', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]