Leflunomide used against Rheumatoid arthritis acts by inhibiting:: (A) Ionisne monophosphate dehydrogenase, (B) Dihydroorotate dehydrogenase, (C) Aldehyde  dehydrogenase, (D) TNF-α receptor
Answer is B. Leflunomide inhibits Dihydroorotate Dehydrogenase and inhibits synthesis of pyrimidine and arrests growth of B-cells.