This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Oxidation of Fatty acids: Ketogenesis, Subject name: Biochemistry
Ketone bodies cannot be utilized by which of the following? 
Select and explain. 
A. Skeletal muscle, B. Red blood cells, C. Brain, D. Heart
B: Red blood cells
Answer: B: Red blood cells 
Explanation: Ans. b. Red blood cells (Ref: Harper's 27/e p190-191)Ketone bodies cannot be utilized Red blood cells.Substrate utilized for energy productionOrganFedFastingStarvationBrainGlucoseGlucoseKetone bodiesQHeartFatty acidQFatty acidKetone bodiesLiverGlucoseFatty acidAmino acidMusclesGlucoseFatty acidFatty acidHeart utilizes fatty acids even in fed state. Brain doesn't use fatty acid for energy production.