This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Biochemistry
[{'content': 'Energy source used by brain in later days of Starvation is \nSelect and explain. \nA. Glucose, B. Ketone bodies, C. Glycogen, D. Fatty acids', 'role': 'user'}, {'content': 'Answer: B \nExplanation: B i.e. Ketone bodies REF: Lippincott book of biochemistry 6th ed.', 'role': 'assistant'}]