Why did civil wars pose a threat to the Roman empire

What was the main argument of plessy in plessy v. ferguson

Why is julius caesar considered an important roman leader? a. his assassination led to a civil war that ended the roman republic.b. his commitment to justice led to the creation of the twelve tablesc. his support for democracy led to expand voting rights for all romansd. his policies as dictator led to a period of peace known as the pax romana

Brainliestttme : ) what demographic changes occurred after world war ii?