Find Equations of the Tangent Lines to the Curve $y=\frac{x-8}{x+8}$ That Are Parallel to the Line

Multiple Choice

Find equations of the tangent lines to the curve $y=\frac{x-8}{x+8}$ that are parallel to the line $x-y=8$ .

A) $x-y=-18.5$
B) $x-y=-4.5$
C) $x-y=-1.5$
D) $x-y=-12.5$
E) $x-y=-15$