Biochemistry HCO3/H2CO3 is the best buffer because it is: A pKa near physiological pH B Its components can be increased or decreased in the body as needed C Good acceptor and donor of H+ ions D Combination of a weak acid and weak base 💡 Explanation HCO3/H2CO3 is the best buffer because it is: ✓ Correct Answer: B. Its components can be increased or decreased in the body as needed