Answer:
D) Because the Roman Catholic Church was the center of the city-state, church officials raised money for the city.
Step-by-step explanation:
The economy of the Roman Empire relayed heavily on their ability to tax the conquered territories and the main taxer of that time was the Catholic Church which gathered money from the Catholics all over the empire and also taxed the other churches for practicing their religion like the jewish people, so eventhough they didn´t have an extensive trade industry they benefited from other conquered territories having a good economy since they were taxing them.