What unify the carolingian empire?

Education, work with Church and Spread of Christianity are what helped to unify the Carolingian Empire.

Explanation: Carolingian Empire can be described as an empire in western and central Europe in the middle ages.

Charlemagne was the first Frankish king who united most of the territories of Western and central Europe. He dashed or gave out money and land to the Christian church and protected the popes, He built a school in his palace  and employed the best teachers to teach in the school.

answer; ok in rural area most people depend on private transportation(cars),pick up truck,donkey and buggy: ),and urban people can walk or ride public transportation,bus,train cab,uber.

it all depends on how long the hours are. i think they wouldn't approve of it. in my opinion.