The black death was initially spread out of asia by merchants and what else?
european middle ages

a. crusader armies

b. catholic missionaries

c. mongol armies

d. livestock and herders

a. Crusader armies

Explanation:

One of the characteristics of the Crusaders was the fact that they travelled long distances on huge ships. These large, fast ships also carried large quantities of goods over long distances. However, along with these goods, they also carried the deadly disease. The pathogen was transported by rats and their fleas. It arrived to Europe around 1348, and by 1350 it had killed between a third and half of the population of the region.

after the roman empire, the catholic church began to unify by taking on many duties of a government.