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
[{'content': 'Which insulin has the late onset of action, longer duration of action, and has no pronounced peak? \nSelect and explain. \nA. NPH, B. Glulisine, C. Glargine, D. Aspa', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Insulin glargine is a soluble, "peakless" (ie, having a broad plasma concentration plateau), long-acting insulin analog. This product was designed to provide reproducible, convenient, background insulin replacement.Insulin glargine has a slow onset of action (1-1.5 hours) and achieves a maximum effect after 4-6 hours. This maximum activity is maintained for 11-24 hours or longer. Glargine is usually given once daily, although some very insulin-sensitive or insulin-resistant individuals benefit from split (twice a day) dosing.Reference: Katzung Pharmacology; 13th edition; Chapter 41; Pancreatic Hormones & Antidiabetic Drugs', 'role': 'assistant'}]