Normal body pH range is

• A. 7.0-7.2
• B. 7.55-7.65
• C. 6.8-7.0
• D. 7.35-7.45

Answer: (D)

Blood pH must stay within a narrow range to keep enzymes and cells functioning properly; the normal arterial pH range is about 7.35 to 7.45. This slight alkalinity is maintained by buffers in the blood, the lungs, and the kidneys working together to regulate acid-base balance. Values outside this window indicate acid-base disturbances: below 7.35 means acidosis, above 7.45 means alkalosis. The provided options show ranges that are either too acidic or too alkaline for normal physiology, so the range around 7.35 to 7.45 is the correct representation of normal body pH.