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
Leflunomide is used in the treatment of : 
Select and explain. 
A. Rheumatoid arthritis, B. Dermatomyositis, C. Bony metastasis, D. Postmenopausal osteoporosis
A: Rheumatoid arthritis
Answer: A: Rheumatoid arthritis 
Explanation: None