This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous (Bio-Chemistry), Subject name: Biochemistry
[{'content': 'pH of the whole blood is estimated in \nSelect and explain. \nA. Plasma, B. Serum, C. RBC, D. Whole blood', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans: a (Plasma) Ref: Vasudevan 4th ed/p. 346.The pH of plasma is 7.4. The pH of plasma is maintained within a narrow range of 7.38 to 7.42', 'role': 'assistant'}]