Answer: D) share enough qualities.
Explanation: a comparison is a consideration or estimate of the similarities or dissimilarities between two things or people. From the given options, the one that expresses the element that will allow us to make an effective comparison, is the corresponding to option D: it is important to determine whether the topics share enough qualities, because it is based on those qualities (that can be similarities or differences) that we are going to make the comparison.
