The correct option is A Sodium dithiosulphatoargentate (I)
There are two of the thiosulphate S2O2−3 ligands. Hence, we need to use di. The cation is Sodium - which almost always exists in its +1 oxidation state in compounds.
The anion is [Ag(S2O3)2]3−.With an anionic charge of -3, silver is definitely in its +1 oxidation state. According to the IUPAC rules, we should have argentate (I) to denote the silver (+1). Hence, the IUPAC name is: Sodium dithiosulphatoargentate (I)