The correct option is C A, C
Buffer solution: A buffer solution is an aqueous solution consisting of a mixture of a weak acid and its conjugate base or weak base and its conjugate acid.
Acidic buffer solution: Acidic buffer are solution of a mixture of weak acid and salt of its conjugate base of that acid with a strong base.
Basic bufer solution: Basic buffer are solution of a mixture of weak base and salt of its conjugate acid of that base with a strong acid.
a)(CH3COONa+CH3COOH) forms acidic buffer as it is a mixture of weak acid and salt of its conjugate base with strong base .
b) (NaCl+NaOH) is not a buffer solution as NaOH is a strong base.
c) (NH4Cl+NH4OH) forms basic buffer as it is a mixture of weak base and salts of its conjugate acid with strong acid.
d) (Na2SO4+H2SO4) is not a buffer solution as H2SO4 is a strong acid.
hence option (A, C) is correct.