Which of the nitrates on strong heating leaves the metal as the residue -

On strong heating lead nitrate gives :

On strong heating lead nitrate gives:

On strong heating lead nitrate gives:

On strong heating lead nitrate gives

On strong heating lead nitrate gives

A metallic nitrate (A) on strong heating leaves behind a residue along with liberation of gases. The metallic nitrate on treatment with H_(2)S//H^(+) gives a black precipitate (B)^(-) insoluble in hot dilute nitric acid, but the precipitate dissolves in aquaregia. Which of the following observation is true ? If the metallic nitrate is dissolved in H_(2)O and then treated with NH_(3)

1.60 g of a metal was dissolved in HNO_3 to prepare its nitrate. The nitrate salt on strong heating gave 2g oxide. The equivalent mass of metal is: