Which of the following topics is the most focused?

scarab beetles
beetles
bugs

The answer can be in terms of ecological perspectives for the complexities of the scrab beetles or bugs.

Explanation:

From what is to be understood here one can see that there is a link to the topics and their complexity so the themes of the insects in their own species' terms will perhaps not be considered here as important..

Their significance in their complexity and differences and what  familiarizes may be the things that do come into play in here.

As the interplay of the elements one can see that the scab is what will be on the top in terms of metaphorical complexity.

your answer would b. the missisipi river

hope i you : )