To determine if it is a parallelogram, use the converse of the parallelogram diagonal theorem. This states that if the diagonals , then the quadrilateral is a parallelogram.

The converse of the parallelogram diagonal theorem says that if the diagonals of a quadrilateral bisect each other, then the quadrilateral is a parallelogram. “Bisect each other” means each diagonal cuts the other into two equal parts, so choice C is correct.

AI-written and checked against the verified answer.