For galvanizing iron which of the following metals is used?

The correct answer is: D. Zinc

Galvanizing is a process of applying a protective zinc coating to iron or steel. This coating helps to prevent the metal from rusting and corroding. Zinc is the most common metal used for galvanizing, as it is highly resistant to corrosion.

Lead is not a good choice for galvanizing, as it is not as resistant to corrosion as zinc. Aluminium is also not a good choice, as it is not as strong as zinc. Copper is a good conductor of electricity, but it is not as strong as zinc and is more expensive.

Therefore, the best metal to use for galvanizing is zinc.