उत्तर : 1. "Chlorine"
व्याख्या :

Answer: A) Chlorine Explanation: Chlorine is the most commonly used bleaching agent.   Bleaching agents are compounds which are used to remove color from substances such as textiles. A bleaching agent is a material that lightens or whitens a substrate through the chemical reaction. The bleaching reactions usually involve oxidative or reductive processes that degrade color systems.