Correct option is B
To prevent rusting and corrosion in electric irons, the plates of the bottom surface and edges are typically made of heavy chromium. Chromium is highly resistant to rust and corrosion, which is why it is commonly used as a protective coating for metals exposed to moisture and heat. This coating helps to maintain the durability and functionality of the electric iron.
Mica is used for insulation purposes, not for preventing rusting.
Asbestos was once used for heat resistance but is not used for rust prevention.
Heavy iron may rust over time and does not provide the same protection as chromium.
