Which detail in the text best reflects the central idea of the passage?

Dictatorships
by Hal Marcovitz
(excerpt from “The Rise of Julius Caesar”)

Sulla was a brutal and relentless dictator. But one enemy who escaped his wrath was Gaius Julius Caesar. Caesar was born in 100 BCE to a wealthy family. As a nephew of Sulla’s opponent Marius, Caesar found himself on Sulla’s list of enemies. No doubt he too would have been killed, but his family intervened, and Sulla reluctantly spared his life. Next, Sulla ordered Caesar to divorce his wife. Caesar refused and fled the city. He joined a Roman army campaigning in Turkey and did not return until after Sulla’s death in 78 BCE.
After returning to Rome, Caesar involved himself in the political intrigues of the republic and began his rise to power. His chief adversary was Sulla’s son-in-law, the powerful general Gnaeus Pompeius Magnus, known familiarly as Pompey. Instead of directly challenging Pompey, Caesar decided to bide his time. He struck an alliance with Pompey, who convinced the Senate to place Caesar in command of a Roman army. Under Caesar, the Romans conquered areas of modern France and Britain, as well as other parts of Europe. It was a campaign that would make Caesar an enormously heroic figure among the Roman people.
As Caesar made his way back to Rome, the Senate ordered him to disband his army. Caesar refused. Instead, on January 10 in 49 BCE, Caesar led his army in an attack on Rome. As his army crossed the Rubicon River to reenter Italy, Caesar is said to have remarked, “Let the dice fly high!”
Caesar’s ploy was not much of a gamble. His army easily swept aside his enemies, including his one-time ally, Pompey. Caesar marched into the city and declared himself dictator. After another four years of warfare in which he pursued his enemies across Europe and Africa, Caesar returned to Rome. He found the once-defiant senate now willing to bow down to his authoritarian power. The Roman senators elected Caesar dictator for life, fearing for their careers and their lives if they did not. Observing how the Roman republic, which had endured for some five centuries, had now crumbled beneath the feet of a dictator, the ancient Roman historian Appian lamented, “The people hoped that [Caesar] would also give them back democracy, just as Sulla had done, who had achieved a position of equal power. However, they were disappointed in this.”