Which of the functions has a vertical asymptote at x = -8?

Question

a. x - 3/ x - 8
b. x/-4
c. (x + 1)(x + 8)/ x + 8
d. x^2 - 6 + 5/ x + 8

I believe the answer is d, but I just wanted to confirm.

Answer 1

any rational function where
(a) the denominator is zero at x = -8
(b) the numerator is not zero at x = -8

If they are both zero, then that is a hole, not an asymptote.