This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Pharmacology
Antidiabetic Safe in liver and renal failure 
Select and explain. 
A. Linagliptin, B. Insulin, C. None, D. Both
D: Both
Answer: D: Both 
Explanation: Linagliptin (oral)-DPP4 inhibitor and insulin(SC) are safe in renal and liver failure. Ref: Katzung 12th ed.