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
Which insulin is never mixed with other insulins ? 
Select and explain. 
A. Lente, B. Aspart, C. Lispro, D. Glargine
D: Glargine
Answer: D: Glargine 
Explanation: None