The correct answer is (a) Leather industry.
Leather is produced from the skin of animals, and the process of tanning leather uses a variety of chemicals, including chromium salts, formaldehyde, and solvents. These chemicals can pollute the air, water, and soil.
The paper industry uses a variety of chemicals, including chlorine, bleach, and sulfuric acid. These chemicals can pollute the air, water, and soil.
The rayon industry uses a variety of chemicals, including sodium hydroxide, sulfuric acid, and carbon disulfide. These chemicals can pollute the air, water, and soil.
The textile industry uses a variety of chemicals, including dyes, solvents, and acids. These chemicals can pollute the air, water, and soil.
However, the leather industry is the largest producer of industrial effluents, and the chemicals used in leather tanning are particularly harmful to the environment.