How does the bicarbonate buffer system maintain systemic pH?

• A. CO2 dissolves in water to form carbonic acid, equilibrates to bicarbonate and H+, maintaining blood pH near 7.4; respiratory and renal systems regulate CO2 and bicarbonate.
• B. Bicarbonate acts as a strong base dominating pH to 7.0.
• C. Buffer system uses phosphate as primary buffer at pH 2.
• D. HCl is produced to keep pH stable.

Answer: (A)