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 NSAID is preferred in treatment of dysmenorrhoea 
Select and explain. 
A. Indomethacin, B. Ketorolac, C. Mefenamic acid, D. Naproxen
C: Mefenamic acid
Answer: C: Mefenamic acid 
Explanation: None