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 of the following is beneficial in NSAID induced gastric ulcer? 
Select and explain. 
A. PGE1 agonist, B. PGE2 agonist, C. PGD agonist, D. PGF2 agonist
A: PGE1 agonist
Answer: A: PGE1 agonist 
Explanation: Prostaglandin analogues exe a cyto-protective effect on the gastric mucosa which prefers them to be employed in the treatment of NSAID induced gastric ulcer. Though both PGE1 analogues (Misoprostol and Risoprostol) and PGE2 analogues (Enoprostol) have shown proven effects on gastric ulcer, only misoprostol is a FDA approved orally active and stable analogue of PGE1 to be used in the treatment of NSAID induced gastric ulcer. Ref: K D Tripathi Textbook of Pharmacology, 5th Edition, Pages 88, 163-64, 593-94; Prostanoids: Pharmacological, Physiological, and Clinical Relevance By Philip Keith Moore, Pages 68, 220