Answer:
Correct answer is D. All of the above.
Explanation:
During Charlemagne's reign most of Western Europe was united under his reign. Most of todays France, countries of Benelux, Germany, even Austria, Switzerland and Italy were part of his empire.
With his military campaign he established a strong reign over all this regions, preventing outsiders to interfere.
Although he wasn't educated himself, he supported art and education, therefore his period is also known as Carolingian Renaissance.
