C. It established that no one, not even a king, is above the law.
Explanation:
The Magna Carta caused the King to have limits and rules to follow depending on the subject. It assured the freedom of the English Church, no longer under the domain of the King. It also demanded the King to return hostages and pardon many who rebelled against him. In many ways, it was a way to limit the King's power, making even the King to have rules to follow.
