Which of these played the biggest role in communication within the roman republic? a) banning of slavery b) irrigation systems c) mountains to the north d) a network of good roads

The correct answer is - D) a network of good roads.

The Romans were well known for their great buildings, but also for their great roads. They were creating nice roads, that were very well connected, everywhere were they managed to get their hands on. They used a specific technique in order to make the roads of better quality and last much longer, and it is no wander that there's lots of remains even nowadays all over the continent where they once ruled.