This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gastrointestinal tract, Subject name: Pharmacology
metaclopromide: 
Select and explain. 
A. inhibit cholinergic smooth.muscle stimulation in the gastrointestinal tract, B. decrease lower esophageal spinchter pressure, C. stimulate D2 receptor, D. enhance colonic activity
D: enhance colonic activity
Answer: D: enhance colonic activity 
Explanation: metaclopromide is aD2 receptor antagonist that increases cholinergic activity by inhibiting presynapyic D2 receptors in GIT . it increases LES tone that is also responsible for anti emetic action. it does not significantly increase colonic motility