The correct answer is C, "A new amendment is proposed in a session of the legislature."
According to the V of the U.S Constitution, there are two ways to amend the constitution. The first one is with two-thirds of both houses of Congress can vote to propose an amendment and the second one is the most used way and it consists on the application of the legislatures of two-thirds that can ask Congress to call a national convention in order to propose the amendments.