The correct answer is C. People began to demand that monarchs respect their natural rights.
The Magna Carta is a significant historical document that illustrates the shift in the relationship between the people and monarchs during the 1200s. It established the principle that the monarch's powers were not absolute and that individuals had certain rights that must be respected, such as the right to a lawful judgment by one's peers. This represented a growing insistence on the need for the rule of law and the protection of individual rights against arbitrary rule by the monarch.