To prove that quadrilateral ABCD is a parallelogram using the properties of the diagonals, you would need to demonstrate that the diagonals bisect each other. This means that the segments created by the intersection point E on the diagonals AC and BD must be equal in length.
Thus, you need to show that \( EB \) is equal to \( ED \).
The correct response is:
EB must be the same length as ED.