A white solid gives off a gas that turns lime water milky when strongly heated. The residue is yellow while hot and becomes white on cooling. The solid is most likely

1. A$\mathrm{CuCO}{}_3$
2. B$\mathrm{ZnCO}{}_3$
3. C$\mathrm{CaCO}{}_3$
4. D$\mathrm{MgCO}{}_3$