1. Recall the thermal decomposition of potassium permanganate

On heating, potassium permanganate decomposes according to the well-known reaction:

$2\,\mathrm{KMnO_4} \xrightarrow{\Delta} \mathrm{K_2MnO_4} + \mathrm{MnO_2} + \mathrm{O_2}$

2. Check oxidation states to understand the products

In $\mathrm{KMnO_4}$, manganese is in the $+7$ oxidation state.

After decomposition:

• In $\mathrm{K_2MnO_4}$, Mn is $+6$
• In $\mathrm{MnO_2}$, Mn is $+4$
• Oxygen is released as $\mathrm{O_2}$

So permanganate undergoes simultaneous reduction to manganate and manganese dioxide.

3. Match with the options

The products formed along with $\mathrm{O_2}$ are:

$\mathrm{K_2MnO_4} \text{ and } \mathrm{MnO_2}$

Thus, the correct option is:

C: $\mathrm{K_2MnO_4}$ & $\mathrm{MnO_2}$

4. Verification with stored answer

Stored correct answer: C

Derived answer: C

They match.