Solution:Concept- The corrosion of iron is rusting of iron due to formation of a flaky oxide layer on the surface of iron which takes place when iron comes in contact with air and moisture.
Now, the salt solution acts as an electrolyte (a material containing free ions that allows it to conduct electricity), causing the iron to lose electrons more quickly, thereby speeding up the rusting process. The process is accelerated by adding salt to the water. Since salt is a strong electrolyte, it contains a large amount of dissociated ions, which greatly accelerates corrosion in salt water.
Therefore, a salt can speed up the rusting process by acting as an electrolyte, allowing the metal (iron) to lose electrons more quickly.
Hence, the correct answer is option (2).