Answer:
Correct answer is The fall of the Roman Empire meant there was less need for a bureaucratic elite.
Step-by-step explanation:
First option is correct as the period after the fall of Western Roman Empire was characterized by a political mess, which led to total decline of literacy.
Second options is not correct as Crusades actually opened trade with the East.
Third option is not correct as Arabs did have written language, different than European languages though.
Last option is not correct as actually church officials were among rare literate people.