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
Effects mediated by H1 histamine receptor include : 
Select and explain. 
A. Inhibition of gastric acid secretion, B. Induction of hepatic cytochrome P450 enzymes, C. Maintenance of a wakeful state, D. Vasoconstriction of arterioles
C: Maintenance of a wakeful state
Answer: C: Maintenance of a wakeful state 
Explanation: None