Which of the following mixtures will make a buffer?
A. 50 mL of 1 M acetic acid +50 mL of 1 M sodium acetate.
B. 50 mL of 1M acetic acid +25 mL of water
C. 25 mL of 1M hydrochloric acid +15 mL of 1M sodium acetate.
D. 50 mL of 1 M sodium acetate +50 mL of water
E. 25 mL of 1M sodium hydroxide +50 mL of 1M sodium acetate