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
[{'content': 'All of the following DPP - 4 inhibitors should be used cautiously in renal insufficiency except? \nSelect and explain. \nA. Sitagliptin, B. Vildagliptin, C. Linagliptin, D. Saxagliptin', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Linagliptin is the only DPP - 4 inhibitor which is safe in renal failure patients.', 'role': 'assistant'}]