Use a Graphing Utility to Graph the Function and Visually $f ( x ) = - x ^ { 3 } + 3 x + 1$

Use a graphing utility to graph the function and visually determine the intervals over which the function is increasing, decreasing, or constant.
$f ( x ) = - x ^ { 3 } + 3 x + 1$

A) increasing on $( - \infty , - 1 )$
decreasing on $( - 1,1 )$
increasing on $( 1 , \infty )$
B) decreasing on $( - \infty , 0 )$
increasing on $( 0 , \infty )$
C) decreasing on $( - \infty , \infty )$
D) increasing on $( - \infty , \infty )$
E) decreasing on $( - \infty , - 1 )$
increasing on $( - 1,1 )$
decreasing on $( 1 , \infty )$