Which of the following descriptions best summarizes the pax romana?

a.) augustus caesar used his broad powers as emperor to usher in a time of peace. roman culture flourished, and ambitious public works projects improved the lives of rome's subjects everywhere.

b.) angry at greece for having supported his rivals, augustus caesar initiated the pax romana by invading and conquering greece.

c.) the pax romana refers to the brief period of tranquility that prevailed in the roman empire under augustus caesar until visigoth invaders plunged rome into the dark ages in 50 bce.

d.) once he had defeated his rivals, augustus caesar reestablished the roman republic. the republic remained in place until its fall to barbarian armies in 500 ce.