Buffer solution can be prepared by mixing

Explanation

A buffer solution is composed of a weak acid with its conjugate base or a weak base with its conjugate acid, allowing it to resist changes in pH upon the addition of small amounts of acid or base. In the case of a weak base and its conjugate salt, the weak base partially dissociates, and the salt provides the necessary conjugate acid for buffering. Strong acids and bases fully dissociate and neutralize each other, which does not provide the necessary conditions for a buffer. A weak acid and a weak base lack the conjugate pairs needed to maintain pH stability, thus failing to form a buffer solution.