Answer:
C. Holy Roman Empire
Step-by-step explanation:
Charlemagne was the dominant and most powerful figure in Europe during his lifetime. He lived in the early Middle Ages, and was ruling over most of Western and Central Europe. Charlemagne was the King of the Franks, and he was also a person that was very religious and had close thighs with Rome and the Pope, often coming to the assistance of the Pope if there were some dangers. Apart from being the King of the Franks, Charlemagne got another title, Holy Roman Emperor, after he was crowned by the Pope himself. That move was of great political and strategic importance for both sides, as Rome secured itself the strongest protector in the region, while Charlemagne got a title that made his authority even greater.