The correct answer is C) imperialism.
As the Roman Republic grew and more land was needed for the people, Rome began a policy of imperialism.
The Roman Empire started to grow more and more, and Roman Emperors decided to use its powerful army to fulfill expansionists ideas and make the Empire grow. The Roman Empire started to conquer many territories and at the cusp of the Empire, Romans extended their territories far away from Rome. The Roman Empire conquered one -third of the known world at that time. Its territory covered Spain, Western, and Eastern Europe, the Middle East, and Northern Africa territories.