Why oil is not stored in galvanized iron pot?

Explanation

Galvanized iron is iron coated with a layer of zinc (Zn) to protect it from rusting. The zinc layer reacts with free fatty acids and moisture present in oil and forms toxic zinc compounds. Zinc salts and metal ions increase the rate of oxidation (rancidity) of oil, thereby reducing its quality. Due to these reactions, the protective zinc layer gradually gets corroded, and the iron underneath comes in contact with moisture and oxygen; as a result, corrosion and rust are clearly observed. Therefore, option (d) is the correct answer.