How do bicarbonate buffering, respiratory CO2 changes, and renal bicarbonate handling maintain pH homeostasis?

How do bicarbonate buffering, respiratory CO2 changes, and renal bicarbonate handling maintain pH homeostasis?

• A. The bicarbonate buffer system buffers H+; the lungs regulate CO2 via respiration; the kidneys reabsorb or generate bicarbonate and excrete H+ to maintain pH.
• B. Bicarbonate buffering is not involved in pH; only lungs regulate pH.
• C. pH is regulated solely by diet; kidneys do nothing.
• D. The bicarbonate system acidifies the blood.

Answer: (A)