A fuel cell converts the chemical energy of a continuously supplied fuel directly into electrical energy through controlled redox reactions, bypassing the combustion-to-heat-to-mechanical-to-electrical chain of a thermal plant. In a hydrogen-oxygen fuel cell, hydrogen is oxidised at the anode and oxygen is reduced at the cathode, with water as the only product. Because it avoids the intermediate heat-engine steps that are limited by the Carnot efficiency, a fuel cell can reach much higher conversion efficiency and produces little pollution. The option that it stores energy is incorrect; a fuel cell generates power only while fuel is supplied and does not store it like a battery. The claim of no electrode reactions is false, since redox reactions at the electrodes are exactly how it works. The option requiring no fuel is wrong because continuous fuel supply is essential. This is the NCERT rationale for fuel-cell technology. Plausibility check: eliminating heat-engine losses logically raises efficiency, consistent with the chosen advantage.