The statement that best proves the dilation of ΔXYZ does not pass through the center of dilation is:
"XY¯¯¯¯¯¯¯¯ and X′Y′¯¯¯¯¯¯¯¯ both have an undefined slope with a center of dilation at (0,0). This proves that the lines are parallel and that the dilation does not pass through the center of dilation."
This is because if the lines corresponding to the pre-image and the image of the dilation have the same undefined slope, it indicates that they are parallel and that the dilation transformation did not occur about the origin (the center of dilation) since parallel lines through a center of dilation would converge or diverge towards the center.