This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General physiology, Subject name: Physiology
[{'content': "Functions of cytoplasmic enzymes of RBC \nSelect and explain. \nA. Maintain pliability of the cell membrane, B. Prevents membrane transpo of ions, C. Keeps the iron of the cells' hemoglobin in the ferric form rather than ferrous form, D. Causes oxidation of the proteins in the RBCs", 'role': 'user'}, {'content': 'Answer: A \nExplanation: Cytoplasmic enzymes of RBC are capable of metabolizing glucose and forming small amounts of adenosine triphosphate. Other functions of the enzymes: (1) Maintain the pliability of the cell membrane(2) Maintain membrane transpo of ions, (3) Keep the iron of the cells&; hemoglobin in the ferrous form rather than ferric form, and (4) Prevent oxidation of the proteins in the RBCs.Reference: Guyton Physiology; 13th edition; Page: 451', 'role': 'assistant'}]