This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Physiology
[{'content': 'In mature erythrocytes the major available anion is \nSelect and explain. \nA. Haemoglobin, B. Chloride, C. Bicarbonate, D. Diphosphoglycerate', 'role': 'user'}, {'content': 'Answer: B \nExplanation: In mature erythrocytes the major available anion is ClRef: Ganong&;s review of medical physiology 23rd edition Page no: 523', 'role': 'assistant'}]