Describe the Increasing, Decreasing, and Constant Behavior of the Function $f ( x ) = 2 x$

Describe the increasing, decreasing, and constant behavior of the function. Find the point or points where the behavior of the function changes. $f ( x ) = 2 x$

A) Increasing on $( - \infty , \infty )$ No change in the graph's behaviour
B) Decreasing on $( - \infty , 1 )$ Incresing on $( 1 , \infty )$ The graph's behaviour changes at the point $( 1 , - 1 )$
C) Increasing on $( - \infty , 0 )$ and $( 2 , \infty )$ Decresing on $( 0,2 )$ The graph's behaviour changes at the points $( 0,0 )$ and $( 2 , - 4 )$
D) Decreasing on $( - \infty , - 2 )$ Increasing on $( 2 , \infty )$ The graph's behaviour changes at the points $( - 2,0 )$ and $( 2,0 )$
E) Decreasing on $( - \infty , 0 )$ Incresing on $( 0 , \infty )$ The graph's behaviour changes at the point $( 0,0 )$