To prove that quadrilateral ABCD is a parallelogram, one of the key properties is that the opposite sides must be equal in length. If we consider the segments EB and ED as part of the diagonals in the context of triangle congruence or quadrilateral properties, the correct option related to EB and ED for ABCD to be a parallelogram would be:
EB must be the same length as ED.
This equality indicates that the segments are equal, which supports the properties of parallelograms where opposite sides (or diagonals of the congruent triangles formed) are equal in length.