Answer: Option D
:
D
Strongly heating Potassium dichromate, Potassium Permanganate or Potassium Chlorate gives oxygen gas.
Heating above ${400}^{\circ }C$, the following reactions takes place
$4K_{2}C{r}_2{O}_7\to 4K_{2}C{r}_2{O}_4+2C{r}_2{O}_3+3O_2$
$2KMn{O}_4\to K_{2}Mn{O}_4+Mn{O}_2+O_2$
$2KCl{O}_3\to 2KCl+3O_2$
Thus all of them release oxygen gas on heating above ${400}^{\circ }C$.These reactions can be used in the preparation of oxygen gas in laboratory.