This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General Pharmacology, Subject name: Pharmacology
A reasonable explanation for the therapeutic effects of ibuprofen or naproxen in primary dysmenorrhea is that these drugs 
Select and explain. 
A. |PGE, and PGF2a, B. selectively inhibit COX 2, C. |LTB,, D. inhibit PLA2
A: |PGE, and PGF2a
Answer: A: |PGE, and PGF2a 
Explanation: PGE, and PGF2a both increase in primary dysmenorrhea, and the therapeutic effects of NSAIDs appear to be due to inhibition of the synthesis of these prostaglandins. Both ibuprofen and naproxen are nonselective COX inhibitors that can inhibit the synthesis of prostacyclin (PGI2 ). NSAIDs do not inhibit phospholipase A2 , and they do not decrease leukotrienes.