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
Which one of the following drugs increases gastrointestinal motility - 
Select and explain. 
A. Glycopyrrolate, B. Atropine, C. Neostigmine, D. Fentanyl
C: Neostigmine
Answer: C: Neostigmine 
Explanation: Ans. is 'c' i.e., Neostigmine Cholinergic drugs and antiadrenergic drugs increase G.I. motility. o Anticholinergic drugs and adrenergic drugs decrease GI motility. o Amongst the given options, neostigmine is cholinergic (anticholinesterase). o Glycopyrrolate and atropine are anticholinergics. o Fentanyl is an opioid and opioids decrease intestinal motility.