The formula of the product formed, when sodium thiosulphate solution is added to silver bromide is

Question

\[\begin {array} {1 1} (a)\;Ag_2S_2O_3 & \quad (b)\;Ag_2S \\ (c)\;Na_3[Ag(S_2O_3)_2] & \quad (d)\;Ag_3[Na(S_2O_3)_2] \end {array}\]