What helped to spread Christianity?

a powerful army of soldiers who had converted
an extensive network of roads and bridges
a high literacy rate around the Roman Empire
a widespread discontent with the Roman authorities

Roads And Bridges

Explanation:

gaius cassius longinus and marcus junius brutus, former enemies of julius caesar who'd joined the roman senate, led caesar's assassination, dubbing themselves "the liberators." and the second one is   the assassination of julius caesar was the result of a conspiracy by many roman senators led by gaius cassius longinus, decimus junius brutus albinus, and marcus junius brutus. they stabbed caesar (23 times) to death in a location adjacent to the theatre of pompey on the ides of march 15 march 44 bc.

which time period is this? or is this story fictional, i'm going to need more info to answer this question