Aqueous solutions of $$HNO_{3}, KOH, CH_{3}COOH$$ and $$CH_{3}COONa$$ of identical concentrations are provided. The pair(s) of solutions which form a buffer upon mixing is(are)

A

$$HNO_{3}$$ and $$CH_{3}COOH$$

B

$$KOH$$ and $$CH_{3}COONa$$

C

$$HNO_{3}$$ and $$CH_{3}COONa$$

D

$$CH_{3}COOH$$ and $$CH_{3}COONa$$