What does it mean that federal law is superior to state law?

What it means is that when the federal government makes a law, the states can not make another law that goes against that law. If the states make a law that is unconstitutional, then the federal government has full jurisdiction to deem the law unconstitutional and veto the law in a sense.

the roman army grew in size and became dominant in the mediterranean region.

c, because the american revolution was from 1765 to 1783.