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
[{'content': "Which long acting insulin can be mixed with rapid acting insulin? \nSelect and explain. \nA. Glargine, B. Degludec, C. Detemir, D. Can't be mixed due to difference in pH", 'role': 'user'}, {'content': 'Answer: B \nExplanation: Traditionally long acting insulins could not be mixed with sho acting insulins due to different pH. However insulin degludec preparation is now available as 70% insulin degludec and 30% insulin aspa and is injected once or twice per day.', 'role': 'assistant'}]