?#8

Okay, so the principle set forth is that people should be rewarded for doing a job proportionately to the effort it costs them to do it. So an easy task for someone with a lot of skill would cost him or her very little effort, and so he or she would get a proportionately small reward. However, for someone with the least skill or natural aptitude, that same task could cost a lot of effort, and so they would get a much bigger reward. Therefore, the argument is made by showing this undesirable consequence that could follow from the general principle.

Why is e the wrong answer. D and e seem very similar to me

The argument isn't saying that the principle cannot be uniformly applied, it is saying that if it is applied, there will be consequences, i.e. "those people with the least skill or natural aptitude for a particular task would be the ones given the most incentive to do it." Therefore, answer choice (E) is not correct since the argument, again, states that following the principle is doable, just not a good idea because it will have consequences, which is what (D) illustrates. Hope that helps! Please let us know if you have any other questions.