A white deliquescent solid X is soluble in water. When heated in a dry tube it evolves a brown gas and a colourless gas that rekindles a glowing splinter, and the residue is yellow while hot and white when cold. The residue dissolves in excess hot aqueous NaOH to give a clear solution. Identify X and the formula and shape of the zinc-containing species in the clear solution.

1. A$\mathrm{Zn}(\mathrm{NO}{}_3){}_2$; $[\mathrm{Zn}(\mathrm{OH}){}_3]{}^{-}$, trigonal planar
2. B$\mathrm{Pb}(\mathrm{NO}{}_3){}_2$; $[\mathrm{Pb}(\mathrm{OH}){}_4]{}^{2-}$, tetrahedral
3. C$\mathrm{Zn}(\mathrm{NO}{}_3){}_2$; $[\mathrm{Zn}(\mathrm{OH}){}_4]{}^{2-}$, tetrahedral
4. D$\mathrm{Zn}(\mathrm{NO}{}_3){}_2$; $[\mathrm{Zn}(\mathrm{OH}){}_6]{}^{4-}$, octahedral