This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
Normal pH of blood is: September 2007 
Select and explain. 
A. 7.3, B. 7.2, C. 7.7, D. 7.4
D: 7.4
Answer: D: 7.4 
Explanation: Ans. D: 7.40Normal pH is 7.35-7.45.There are a series of buffers which help the plasma resist any change in pH. Some of them include: the hemoglobin in the red blood cells, other plasma proteins, the bicarbonate buffer and the phosphate buffer.