Determine Which of the Following Is Not True for the Graph

Multiple Choice

Determine which of the following is not true for the graph of $f ( x ) = x ^ { 3 } - 9 x ^ { 2 } + 15 x$

A) ƒ is continuous on $( - \infty , \infty )$
B) ƒhas a relative maximum at x = -1.
C) ƒ has a relative minimum at x = 5.
D) ƒ has a point of inflection at x = 3.
E) ƒ is concave downward on $( - \infty , 3 )$