This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Blood: RBCs, Anemia, and Polycythemia, Subject name: Physiology
Biconcave shape of RBC is useful in all aspects except: 
Select and explain. 
A. Helps in passing through capillaries, B. Helps in cellular metabolism, C. Increased surface area diffusion of gases, D. Prevent osmotic lysis
B: Helps in cellular metabolism
Answer: B: Helps in cellular metabolism 
Explanation: Ref: Pal GK. Red Blood Cells. In: Textbook of Medical Physiology. Ahuja Publishing House. 2007: 8: 63.Explanation:Advantages of biconcavity of RBCsWithstand lysis when exposed to hypotonic environmentBetter exchange of gasEasy movement through capillariesMetabolism in RBCNo nuclei, mitochondria, ribosomesTCA cycle is absentGlucose oxidation - 90% - Embden - Mayerhoff pathway: 10% - HMP shunt