This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Diabetes Mellitus, Subject name: Medicine
Which of the following is known as peakless insulin? 
Select and explain. 
A. Isophane, B. Degludec, C. Glulisine, D. Lispro
B: Degludec
Answer: B: Degludec 
Explanation: Long acting insulin have onset of action after 30minutes of administration and do not exhibit a peak action unlike other forms of insulin. They are designed to provide constant values in blood for the entire day. Insulin type Onset of action Peak action Effective duration Glargine 0.5-1hr Peakess/ flat 24 hours Detemir 0.5-1hr Peakless/flat 17 hours Degludec 0.5-1 hr Peakless/flat 42 hours