XZ ⊥ WY (option C)
Step-by-step explanation:
Information from the diagram:
XW = YZ (tick marks indicate it)
XY = WZ (tick marks indicate it)
For a parallelogram:
EX = EZ
This is because the diagonals bisect each other
For a rhombus:
EX = EZ
In a rhombus the diagonals are perpendicular to each other
The diagonlas here are: XZ and WY
So for the quadrilateral to be a rhombus, diagonals will be perpendicular to each other
Hence, XZ ⊥ WY (option C)