Which of the following metal bicarbonate will give metal oxide and  ${\mathrm{CO}}_2$ on heating?

$\mathrm{Mg}{\left({\mathrm{HCO}}_3\right)}_2$ gives metal oxide and carbon dioxide on heating. The following reaction is obtained as follows,

$\begin{array}{l}\mathrm{Mg}{\left({\mathrm{HCO}}_3\right)}_2\stackrel{\mathrm{\Delta }}{\to }{\mathrm{MgCO}}_3+{\mathrm{CO}}_2+{\mathrm{H}}_2\mathrm{O}\\ \mathrm{Mg}{\left({\mathrm{HCO}}_3\right)}_2\stackrel{\mathrm{\Delta }}{\to }\mathrm{MgO}+{\mathrm{CO}}_2\end{array}$

Hence, the option B is correct.