Answer:
A
Step-by-step explanation:
Hyperbolic geometry is defined as a non-Euclidean geometry.
(invalidating the fifth postulate of Euclid's five fundamental postulates)
Choice B and D can be eliminated because this has nothing to do with perpendicular lines.
Choice C should be eliminated as well since that's exactly the fifth postulate of Euclid's five fundamental postulates
We are left with A by the process of elimination
Y=cd-8
Add 8 to each side giving you
y+8=cd
Divide by d on each side giving you
C=(y+8)/d