Answer: A) A dominating nation with extensive territories and a powerful ruler, such as Rome, is known as an empire.
Step-by-step explanation:
An empire is defined as an extensive group of states or countries which is ruled by a single person. This is the reason why letter A is the correct statement. On the other hand, statement B is false because the republic was not known as a socialist government. C is incorrect because it was established around the year 450 B.C. and D is incorrect because it lasted around 500 years.