Concept:Blood plasma is the liquid component of blood and has a slightly alkaline pH, which is tightly regulated by buffer systems.
Explanation:The normal pH of human blood, including plasma, is approximately 7.4.
This pH is maintained by bicarbonate and other buffers to keep the body in a healthy range.
A pH below 7.35 indicates acidosis, and above 7.45 indicates alkalosis.
Among the given options, 7.4 is the correct physiological value.
Plasma constitutes about 55% of blood volume and is mostly water (92%).
Answer:Option A, 7.4.