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
Agonistic action at which of the following adrenergic receptors results in the reduction of aqueous secretion ? 
Select and explain. 
A. β1 receptor, B. β2 receptor, C. M2 receptor, D. α2 receptor
D: α2 receptor
Answer: D: α2 receptor 
Explanation: α2 receptors on ciliary epithelium when stimulated, reduces aqueous humor secretion.