$\text{ When }{\mathrm{KClO}}_3\text{ is heated, it decomposes into }\mathrm{KCl}+{\mathrm{O}}_2\text{. If some }{\mathrm{MnO}}_2\text{ is added, the reaction goes much faster because? }$

${\mathrm{MnO}}_2\text{ decomposes to give }{\mathrm{O}}_2$

${\mathrm{MnO}}_2\text{ provides heat by reacting }$

${\mathrm{MnO}}_2\text{ acts as a catalyst }$

$\text{ Better contact is provided by }{\mathrm{MnO}}_2$