Give the Equation of the Oblique Asymptote, If Any, of the Function

Multiple Choice

Give the equation of the oblique asymptote, if any, of the function.
- $$f ( x ) = \frac { x ^ { 2 } - 6 } { 36 x - x ^ { 4 } }$$

A) $y = 36 x$
B) $y = 0$
C) no oblique asymptote
D) $y = x - 6$