Rory is trying to identify a tree from one of its leaves. a question on the dichotomous key that he is using asks whether the leaf has 3-5 lobes or more than 5 lobes. rory cannot tell whether the leaf in his hand has 5 or 6 lobes. what should rory do to continue identifying the tree?
look at other leaves from the same tree, and count how many lobes they have.
skip this question, since one question does not make a difference.
start over from the beginning of the dichotomous key.
find a different dichotomous key to use that does not ask this question.

The answer would be:

Look at other leaves from the same tree, and count how many lobes they have.

If you'd like to know why, read on:

A dichotomous key helps identify an organism based on observable traits. One option leads to another question, which would be more specific based on the choice made before it, so skipping it would not be a good option. Even if you start over from the beginning of the dichotomous key, you will end up with the same question because you are examining the same thing.

Looking at the other leaves is the best choice because the other leaves are part of the organism you are observing, so it would be the same thing.