Give the Equations of Any Vertical Asymptotes $$f ( x ) = \frac { x - 1 } { x ^ { 2 } + 1 }$$

Multiple Choice

Give the equations of any vertical asymptotes.
- $$f ( x ) = \frac { x - 1 } { x ^ { 2 } + 1 }$$

A) $x = 1$
B) $x = - 1$
C) none
D) $x = 1 , x = - 1$