$_p K_a$ of a weak acid (HA) and $_pK_b$ of a weak base $(BOH)$ are 3.2 and 3.4, respectively.The pH of their salt (AB) solution is :

Question

$\begin{array}{1 1} (1) 7.0 \\ (2) 1.0 \\ (3) 7.2 \\ (4) 6.9 \end{array}$