With caesar augustus’s rise to power, rome:
a. became a powerful empire.
b. was invaded by outsiders.
c. lost its battles with its enemies.
d. ruled the entire world.

A, because they never ruled the entire world at that time they were just a really powerful army and they were strong. Yes they did have some downfalls but Augustus had a strong army.

A. He started the Pax Romana in which there was Roman peace and Augustus Caesar helped Rome expand and be a powerful empire. 
Hope this helps.