dynamo
Ni-Cd cell
fuel cell
electrolytic cell
Correct option is C. fuel cell
The combustion reactions are redox reactions. Hence, they are used to produce electricity.
Fuel cells are the galvanic cells in which the energy of combustion of fuels is directly converted into electrical energy.
In the fuel cells, the reactants are continuously supplied to the electrodes from the reservoir.
The fuel used is hydrogen gas, methane or methanol.