The answer is C. i just took the test and i got it right.
They had members in public office
The old Roman Republic from its Empire had it's Emperor, Hail Caesar, with nearly absolute power. But being a republic then, they also had a Senate of which the Senators were elected from the people, as government's representatives of and for the people. This concept can be adapted to resemble our current legislative branch, vis-à-vis Congress. And of course our executive, commander-in-chief, stems from a less domineering figure of Rome's Emperor Caesar.
The Answer is going to be C.
Hope this helps :)