By-product obtained by soap industry is A. Caustic soda B. Glycerol C. Naphthalene D. Caustic potash

The correct answer is: B. Glycerol

Glycerol is a by-product of the soap industry. It is a colorless, odorless, viscous liquid that is sweet-tasting and non-toxic. It is used in a variety of products, including cosmetics, pharmaceuticals, and food.

Caustic soda (sodium hydroxide) and caustic potash (potassium hydroxide) are both used in the soapmaking process, but they are not by-products. They are the main ingredients in soap, and they are what give soap

its cleaning properties.

Naphthalene is a white, crystalline solid that is used in mothballs and other products to repel insects. It is not a by-product of the soap industry.