You have enrolled ___ more than one class.

Correct Answer: B. Into

Enrolled” is a transitive verb, and when used in the context of joining or registering for classes, it is followed by the preposition “into.” “Into” is used to indicate movement towards a point in space or time, and in this case, it signifies the action of joining or becoming a part of the classes. Therefore, the correct preposition to use with “enrolled” in this context is “into.