How do correlation and causation differ

What was the land like around rome? dry rocky fertile volcanic

Historians have recently discovered a historical journal published in the early twentieth century. the journal contains facts based on original sources about the downfall of the early byzantium empire. historians consider this long-lost journal to be a breakthrough in their understanding of the byzantium empire. based on this information, the journal is a source.

How did inca develop their road system? a) they used mortar to hold the stones together. b) they built suspension bridges over rivers. c) they mixed copper and stone together to make the blocks. d) they laid roads in the cities, not in the less densely populated deserts.