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 $( - \infty , \infty )$
decreasing on $( - \infty , - 1 )$

E) increasing on $( - 1,1 )$
decreasing on $( 1 , \infty )$