Verified Answer :

that is wher you divide by 0
that is when denomenator is equal to 0
also, there is a hole whenever you simplify
\(\frac{x^2-16}{6x-24}= \frac{(x-4)(x+4)}{6(x-4)} = \frac{x+4}{6}\)
the x-4 canceled out so there is no assemtote
but since it cancled outht ere is a hole at x-4
x-4=0
x=4

answer is D