Which of the following statements is true about the Roman Republic?

I- It was preceded by the Roman Monarchy.
II- It was characterized by the struggle between plebeians and patricians.
III- It was a period of territorial expansion and wars against Carthage.
IV- It was followed by the Roman Empire.
a) Only I and II are true.
b) Only II and III are true.
c) Only III and IV are true.
d) All statements are true.