What was the most daunting challenge of Charlemagne's reign of power?

New zoya is a country of english-speaking people and has a very profitable economy. which of the following countries is most likely to be the closest to new zoya in terms of cultural distance? sulfura, which has a very profitable economy and where people speak sulfuran valyria, where people speak english and have a low standard of living danver, which has the same wealth and per capita income as new zoya novalandia, which is located close to new zoya and is easily accessible by road