Explain how to use the midpoint formula to prove or disprove that ABCD is a parallelogram. A) Prove that AC and BD do not have the same midpoint. The diagonals of a parallelogram cannot have the same midpoint. B) Prove that AD and BC have the same midpoint. All sides of a parallelogram are congruent; therefore, they have the same midpoint. C) Prove that AC and BD have the same midpoint. The diagonals of a parallelogram bisect each other; therefore, they have the same midpoint. D) Prove that AB and CD do not have the same midpoint. All sides of a parallelogram are congruent; therefore, they have different midpoints.