Which one of the following is commonly used for pulp bleaching in the paper industry?

Bleaching of wood pulp is the chemical processing carried out to decrease the color of the pulp, so that it becomes whiter.Alkaline hydrogen peroxide is the most commonly used bleaching agent for mechanical pulp. It selectively oxidizes non-aromatic conjugated groups responsible for absorbing visible light. The decomposition of hydrogen peroxide is catalyzed by transition metals.