This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T., Subject name: Physiology
Unlike other GI secretions, salivary secretion is controlled almost exclusively by the nervous system and is significantly inhibited by: 
Select and explain. 
A. Atropine, B. Pilocarpine, C. Cimetidine, D. Aspirin
A: Atropine
Answer: A: Atropine 
Explanation: Ans. A. AtropineSalivary secretion is inhibited by atropine. Atropine is an anticholinergic drug that competitively inhibits ACh at postganglionic sites, inhibiting parasympathetic activity. Pilocarpine actually stimulates salivation because of its muscarinic action. Cimetidine is an antagonist for the histamine H2 receptor. Aspirin is the most widely used analgesic (pain reducer), antipyretic (fever reducer), and anti-inflammatory drug. Omeprazole inhibits the H+/K+-ATPase and, thus, inhibits acid secretion.