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 disease modifying anti–rheumatoid drugs is a prodrug ? 
Select and explain. 
A. Etanercept, B. Nimesulide, C. Sulfasalazine, D. Colchicine
C: Sulfasalazine
Answer: C: Sulfasalazine 
Explanation: None