Which of the following best describes the relationship between a conjugate acid and a conjugate base?
A) A conjugate acid donates a proton to become a conjugate base, and a conjugate base accepts a proton to become a conjugate acid.
B) A conjugate acid and a conjugate base are two forms of the same compound in different states of matter.
C) A conjugate acid always has a higher pH than its conjugate base.
D) A conjugate acid and a conjugate base are always present in equal concentrations in a solution.