Which of these best describes how Charlemagne changed Europe?
A. Charlemagne and King William conquered England at the battle of Hastings in 1066.
B. Charlemagne consolidated most of Western Europe as founder of the Holy Roman Empire.
C. Charlemagne was the leader of the Protestant Reformation and a friend of Martin Luther.
D. Charlemagne was the King of England and wanted to keep Europe separate from England.