19. If $f ^ { \prime \prime } ( x ) = x ( x + 1 ) ( x - 2 ) ^ { 2 }$, then the graph of $f$ has inflection points when $x =$ (A) - 1 only (B) 2 only (C) - 1 and 0 only (D) -1 and 2 only (E) $- 1,0$, and 2 only
19. If $f ^ { \prime \prime } ( x ) = x ( x + 1 ) ( x - 2 ) ^ { 2 }$, then the graph of $f$ has inflection points when $x =$\\
(A) - 1 only\\
(B) 2 only\\
(C) - 1 and 0 only\\
(D) -1 and 2 only\\
(E) $- 1,0$, and 2 only\\