Explanation:

A fuel cell in order to produce electricity burns hydrogen.

• A fuel cell is nothing but a reaction in which hydrogen bonds in the presence of oxygen to produce water.
• This results in the production of a large amount of heat which is converted into electricity.
• This electricity is then make to run in a closed circuit resulting in the production of current and running of appliance- a fuel cell is a modern cell which is developed to produce electricity without causing any damage to the exhaustible natural resources.

Hence option 3rd is correct.