Bleaching action of ${H_2}{O_2}$ is due to its:
A. Oxidising nature
B. Reducing nature
C. Acidic nature
D. Thermal instability

Hint: Hydrogen peroxide is a chemical compound with the chemical formula ${H_2}{O_2}$. In its pure form, it is a very pale blue liquid, slightly more viscous than water. This means that it has less fluidity than water. Hydrogen peroxide is the simplest peroxide (a compound with an oxygen–oxygen single bond). It is used as an oxidizer, bleaching agent, and as an antiseptic.

Complete step by step answer:
The bleaching action of any substance is the process in which when a particular substance is added to the chromophore containing complexes, the substance helps in the breaking of the chemical bonds in the solution and thus releasing the color of the material by a simple process of oxidation.
\[{H_2}{O_2}\] or hydrogen peroxide acts as a strong oxidizing agent both in acidic and basic media. When hydrogen peroxide is added to a cloth or any material which has coloration on it, it breaks the chemical bonds of the chromophores (color producing agents). Thus, the bleaching action of \[{H_2}{O_2}\] is due to the oxidation of coloring matter by nascent oxygen. The reaction that takes place in the hydrogen peroxide is as follows:
${H_2}{O_2} \to {H_2}O + [O]$
The nascent oxygen is highly reactive and attacks over the chemical bonds of the coloring centers and oxidizes them as soon as it comes in contact with them.

Thus, the correct option is A. oxidising nature.

Note:
Hydrogen peroxide has an open-book structure. It finds various applications in our day to day lives. It is used in bleaching, in the production of various organic compounds, as a disinfectant, in the removal of blood stains, as a rocket propellant, in fish-keeping and horticulture, etc.