In the rectangular coordinate plane points X and Z lie on the same line through the origin and points W and Y lie on the same line through the origin. If a^2 + b^2 = c^2 + d^2 and e^2 + f^2 = g^2 + h^2, what is the value of length XZ - length WY?
A. -2
B. -1
C. 0
D. 1
E. 2
The OA is C.
Source: Manhattan GMAT
