The statement that best explains the differences between the democracy of the Athenian polis and the structure of the Roman Republic is:
The senate of the Roman Republic was composed of wealthy patrician magistrates whereas the Athenian ecclesia and Council of 500 were made up of various citizens drawn by lot from different territories within Athens.
This statement highlights the contrasting systems of representation and social class in the governance of the two polities. In Athens, a broader segment of the population had the opportunity to participate in government, while in the Roman Republic, political power was predominantly held by the patrician class.