How did geography influence the development of the Roman Empire?

Rich volcanic soil makes the Po and Tiber river valleys ideally suited for agriculture. Historian Mike Anderson notes that volcanic ash made the soil near Rome some of the best in all of Europe. The surplus also helped Rome to establish trade ties with other Mediterranean powers, enhancing the city's economic might.

what the first or next guy says

d. it spread christianity. i just took the test and got it right.