Which of the following statements is an example of a historical argument?

a. how many people lived in the roman empire at the height of its power?
b. writing about roman history is a time-consuming and draining process for historians.
c. after the assassination of julius caesar, augustus caesar won a civil war and became roman emperor.
d. rome collapsed because of internal weaknesses, not because of attacks from foreign invaders.

The correct answer for the given question above would be option D. The statement that is an example of a historical argument would be this:  Rome collapsed because of internal weaknesses, not because of attacks from foreign invaders. When we say argument, this means that it is a set of propositions made to show that a particular conclusion is true. It is not simply a statement of opinion, but rather an attempt to give reasons. Hope this answer helps.