Final answer:
The Frankish kings had an alliance with the Byzantine Empire that helped reestablish Roman culture in Western Europe. Therefore, the correct option is a).
Step-by-step explanation:
The Frankish kings had an alliance with the Byzantine Empire that helped reestablish Roman culture in Western Europe.
This alliance involved the Frankish kings pledging allegiance to the Roman emperor in Constantinople, in return for recognition and legitimacy of their rule. The Frankish kings also made efforts to preserve Roman culture by recording their laws in Latin and adopting the Latin language.
The alliance with the Byzantine Empire helped maintain diplomatic and economic ties across Western Eurasia and played a significant role in preserving the classical past and paving the way for stability and growth in the High Middle Ages.
Therefore, the correct option is a).