URGENT

kings were careful to respect the priests' right and powers because

Because of the coronation.

Explanation:

Priests during the Middle Ages were authorized to crown kings. Charlemagne, as one of the most powerful rulers of the Middle Ages, respected priests. The ruler was believed to have come to this position by God's will as it was more specifically called "HIS determination" (of God). Therefore, the priest was a kind of mediator between the spiritual and the secular. That is why kings respected priests.

c it says nothing about connecting those 2 seas.