Answer:
Option C
Step-by-step explanation:
A buffer aqueous solution consists of
a) either a weak acid along with its conjugate base
b) or a weak base along with its conjugate acid.
This is used to prevent change in the pH of a solution whenever an acid or a base is added. The pH of a buffer depends upon the ratio of base to acid and this ratio is determined by the Ka value and Henderson-Hasselbalch equation. An ideal buffer has equal amounts of acid and conjugate base
Hence, option C is correct