Locate All Inflection Points Of $f ( x ) = x ^ { 4 } + 6 x ^ { 3 } - 24 x ^ { 2 } + 26$

Multiple Choice

Locate all inflection points of $f ( x ) = x ^ { 4 } + 6 x ^ { 3 } - 24 x ^ { 2 } + 26$ .

A) (1, 9) and (-4, -486)
B) (1, 9)
C) None
D) (0, 26)