Reactions involve the gain or loss of oxygen or hydrogen by substances.

Statement A: Oxidation is the loss of oxygen and gain of hydrogen.
Statement B: Reduction is the loss of hydrogen and gain of oxygen.

Both statements A and B are incorrect.

The correct answer is Option (4) → Both statements A and B are incorrect.

Statement A: Oxidation is the loss of oxygen and gain of hydrogen. (Incorrect)
Statement B: Reduction is the loss of hydrogen and gain of oxygen. (Incorrect)

Let’s correct them:

Oxidation → Gain of oxygen or loss of hydrogen.

Reduction → Gain of hydrogen or loss of oxygen.