$pK_{a1}$ and $pK_{a2}$ of $H_2CO_3$ are 6.38 and 10.26 respectively. The $pH$ of 1 M and 0.1 M $NaHCO_3$ are

Question

(a) 8.32, 7.32

(b) 7.32, 8.32

(c) 8.32, 8.32

(d) 7.32, 7.32