Explanation

(d)
$Ag_{2}CO_{3} \rightleftharpoons 2{Ag}^{+} + {CO}_{3}^{2 -}$
Due to the common ion effect, the solubility decreases, so the solubility of $Ag_{2}CO_{3}$ would be greatest 1 L of 0.05 M $NH_{3}$ due to the absence of common ion either ${Ag}^{+}or\ {CO}_{3}^{2 -}$. ${Ag}^{+}form\ complex\ with\ NH_{3}$.
${Ag}^{+} + 2NH_{3} \rightleftharpoons \left\lbrack Ag\left( NH_{3} \right)_{2} \right\rbrack^{+}$