Let $f ( x ) = \frac { | x | } { x }$

Multiple Choice

Let $f ( x ) = \frac { | x | } { x }$ The set of all vertical asymptotes of ƒ is

A) $\{ x = 0 \}$
B) $\{ x = 1 \}$
C) $\{ x = - 1 \}$
D) $\{ x = 0 , x = 1 \}$
E) $\varnothing$