Answer the following question given this paragraph: 

called an alkaline battery when adapted to operate under alkaline conditions. Button batteries have a high output-to-mass ratio; lithium–iodine batteries consist of a solid electrolyte; the nickel– cadmium (NiCad) battery is rechargeable; and the lead–acid battery, which is also rechargeable, does not require the electrodes to be in separate compartments. A fuel cell requires an external supply of reactants as the products of the reaction are continuously removed. In a fuel cell, energy is not stored; electrical energy is provided by a chemical reaction.


Q: In a fuel cell, energy is not stored; electrical energy is provided by what?

 Choices:

- fusion reaction

- carbon reaction

- consumption reaction

- chemical reaction

A:
chemical reaction
