Identify the correct order of solubility of $Na_2S, CuS$ and $ZnS$ in aqueous solution

Question

(a) $CuS > ZnS > Na_2S$
(b) $ZnS > Na_2S > CuS$
(c) $Na_2S > CuS > ZnS$
(d) $Na_2S > ZnS > CuS$