The most likely reason why Napoleon could be classified as an enlightened monarch was because

he declared himself an enlightened monarch.

he implemented certain enlightenment ideals.

the Pope blessed him as an enlightened monarch.

in comparison to his predecessor, he was enlightened.

The answer is letter C. He had implemented some of the ideas of enlightenment such as the Social Contract which state that his legitimacy to rule was the decision of the majority. Bonaparte had won the majority’s decision after French Revolution and thus crowned himself as the King of France