The correct answer is:
A. An agreement between people to follow laws and be governed by a leader or leaders.
The social contract concept is part of a theory in moral and political philosophy about the legitimacy of the authority of the state over the individual.
Social contract theory states that individuals submit to the authority of a ruler, or to the decision of a majority, by surrendering some of their freedoms. In exchange, their other rights, as well as the social order, are guaranteed.