Which of the following electrochemical cells would use up the largest quantity of electricity at 25°C? All right, so here they're saying would use up. This means that it's consuming electricity. Here we have electrochemical cells A to D, each with a standard cell potential, some being negative, some being positive.
Remember, if you're using up electricity, you're consuming electricity, which means that your standard cell potential would be negative. That means that options B&C are out. Here we have -0.75 V versus -1.42 V.
Here D is the answer because not only is it negative in terms of its standard cell potential, it is the most negative. This would mean that it consumes or uses up the largest amount of electricity. So again, our final answer here would be option D.