When argentite ore is leached with dilute aqueous sodium cyanide in the presence of air, silver passes into solution as

1. A$\mathrm{Na}{}_2[\mathrm{Ag}(\mathrm{CN}){}_2]$
2. B$\mathrm{Na}[\mathrm{Ag}(\mathrm{CN}){}_2]$
3. C$\mathrm{AgCN}$
4. D$\mathrm{Na}{}_3[\mathrm{Ag}(\mathrm{CN}){}_4]$