Explanation:
The correct answer is A. +7.

In potassium permanganate (KMnO₄), the oxidation state of manganese (Mn) is +7.

Here's the reasoning:

Potassium (K) has an oxidation state of +1.

Oxygen (O) typically has an oxidation state of -2.

The overall charge of the permanganate ion (MnO₄⁻) is -1.

Using the equation for the oxidation states in the permanganate ion:

Mn oxidation state
+
4
×
(
−
2
)
=
−
1
Mn oxidation state+4×(−2)=−1
Mn oxidation state
−
8
=
−
1
Mn oxidation state−8=−1
Mn oxidation state
=
+
7
Mn oxidation state=+7
Thus, the oxidation state of manganese in potassium permanganate is +7.