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
A patient with gastric ulcer is prescribed misoprostol. It is an analogue of? 
Select and explain. 
A. PGE1, B. PGE2, C. PGF2a, D. PGI2
A: PGE1
Answer: A: PGE1 
Explanation: Misoprostol is a synthetic PGE1 analogue. It inhibits gastric acid secretion and exes mucosal-protective propeies. Misoprostol in combination with mifepristone or methotrexate is highly effective in the termination of the early pregnancy. Must know: PGE2 analogue is dinoprostone, PGF2a analogue is carboprost, and PGI2 analogue is beraprost sodium. Ref: Desk Reference of Clinical Pharmacology, Second Edition By Manuchair S. Ebadi, 2008, Page 447; Goodman and Gillman's, 11th edition, Page 626