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: Medicine
[{'content': 'A 41-year-old male patient presented with recurrent episodes of bloody diarrhoea for 5 years. Despite regular treatment with adequate doses of sulfasalazine, he has had several exacerbations of his disease and required several weeks of steroids for the control for flares. What should be the next line of treatment for him? \nSelect and explain. \nA. Methotrexate, B. Azathioprine, C. Cyclosporine, D. Cyclophosphamide', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]