What one of the five is least like the other four?

It will depend on what your basis is going to be for making a decision. If you would base it on what people consider to be a fruit and a vegetable, the answer will be letter E which is the apple. If you would base it on appearance, you can see that all of them will have similar shapes except for beans which may grow differently from the other plants and trees.

You may have your own assessment of what is different from all the others. It is helpful if you would be able to identify the one that is considered to be the different one from a set.