What was the main reason the roman republic divided its government into three parts?

The highest positions in thegovernment were held by two consuls, or leaders, who ruled the Roman Republic. A senate composed of patricians elected these consuls. ... Tradition dictated that patricians and plebeians should be strictly separated; marriage between the two classes was even prohibited

Iwould say a, due to the fact these routes display many things that would be useful and provide explanations for how states are known.