Which of the following thermal decomposition yields a basic as well as an acidic oxide? 

The following result is obtained as thermal decomposition of  ${\mathrm{CaCO}}_3$

${\mathrm{CaCO}}_3\to \mathrm{CaO}+{\mathrm{CO}}_2$

$\mathrm{CaO}$ is a basic oxide and  ${\mathrm{CO}}_2$ is an acidic oxide. When calcium carbonate is heated, calcium oxide and carbon dioxide are produced. Heat is necessary for the process of thermal breakdown. Hence thermal decomposition of calcium carbonate gives both basic and acidic oxide.