Correct statements among the following are :

A) At 298 K, ${\text{p}}^{\text{H}}$ of an acidic buffer is always less than seven.

B) Buffer capacity of acidic buffer is maximum when its ${\mathrm{P}}^{\mathrm{H}}={\mathrm{P}}^{{\mathrm{K}}_{\mathrm{a}}}$(of weak acid present in it).

C) Equimolar mixture of ${\text{NH}}_{\text{4}}\text{OH}$ and HCl can act like a basic buffer.

D) A mixture of ${\text{NH}}_{\text{4}}\text{Cl}$ (excess) and NaOH acts as buffer.

A) At 298 K, P^H of an acidic buffer can be greater or lesser than or equal to 7

B) Buffer capacity of acidic buffer is maximum when its p^H is equal to p^K_a

C) Equimolar mixture of NH₄OH and HCl cannot act like a basic buffer

     Mixture of excess weak base and limited strong acid can act like buffer

D) ${\mathrm{NH}}_4^{+}$ (excess) + NaOH acts as a buffer.