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
Which of the following insulin is rapidly acting? 
Select and explain. 
A. Insulin lispro, B. Regular insulin, C. Insulin glargine, D. NPH
A: Insulin lispro
Answer: A: Insulin lispro 
Explanation: Ref: KDT 6th ed. pg. 259Insulin typeOnset of action (hr.)Duration of action (hr)Ultrashort (Rapid Acting) Insulin LisproInsulin AspartInsulin Gluilisine15 - 30 minutes3-5 hrsShort actingRegular insulin30-60 minutes6-8 hrsIntermediate actingInsulin lenteNeutral protamine hagedorn (NPH)/lsophane insulin1-2 hrs16-20 hrsLong ActingInsulin GlargineInsulin Detemir Insulin Degludec2-4 hrs16-24 hrsDegludec: >24 hoursInhaled insulin(Human insulin)-Liquid form5-10 minutes3-5 minutesMost common side effect of insulin: hypoglycemiaDOC for Diabetic ketoacidosis (DKA): Regular insulin