This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
The major fuel for the brain after several weeks of starvation 
Select and explain. 
A. Glucose, B. Fatty acid, C. Beta hydroxybutyrate, D. Glycerol
C: Beta hydroxybutyrate
Answer: C: Beta hydroxybutyrate 
Explanation: The major fuel for brain in prolonged starvation is ketone bodies (Beta hydroxybutyrate, acetoacetate).