The Roman Republic became an empire due to it's military leaders seizing national power.
By using the process of elimination, you can determine that the Roman Repubic:
-Did not conquer Europe
-Only reached 2 continents
-Did not have the best worldwide economy.
Leaving C to be the only choice.
Answer:
The answer would be c because after the civil war ended in Rome, Julius caesar's son Augustus took over in Rome seizing power over the city rome!