The statement that accurately summarizes the figures and events that led to the fall of the Roman Republic is:
The Roman Republic fell due to the first civil war and political struggles between the Populares and Optimates.
This response highlights the internal conflict during the first civil war between Julius Caesar and Pompey, which was driven by the broader political struggle between the Populares (who represented the common people) and the Optimates (who represented the aristocratic elite), ultimately leading to the collapse of the Republic.