Biochemistry Which of the following is the most effective buffer for pH of 7.4? A Carbonic acid buffer with pKA-6.1 B Phosphate buffer with pKA of 6.9 C Glutamate buffer with pKA-8.7 D Acetate buffer with pKa 4.5 💡 Explanation Which of the following is the most effective buffer for pH of 7.4? ✓ Correct Answer: B. Phosphate buffer with pKA of 6.9