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
Prucalopride drug is ? 
Select and explain. 
A. 5HT4 agonist, B. 5HT2b agonist, C. 5HT2b antagonist, D. 5HT2a agonist
A: 5HT4 agonist
Answer: A: 5HT4 agonist 
Explanation: Ans. A. 5HT4 agonist* Prucalopride is a drug acting as a selective, high affinity 5-HT4 receptor agonist which targets the impaired motility associated with chronic constipation, thus normalizing bowel movements.* Approved for use in Europe in 2009.* Prucalopride, a first in class dihydro-benzofuran-carboxamide, is a selective, high affinity serotonin (5-HT4) receptor agonist with enterokinetic activities.* Prucalopride alters colonic motility patterns serotonin 5-HT4 receptor stimulation: it stimulates colonic mass movements, which provide the main propulsive force for defecation.* The observed effects are exeed highly selective action on 5-HT4 receptor.* Prucalopride has >150-fold higher affinity for 5-HT4 receptors than for other receptors.