Find All the Zeros (Real and Complex)of the Function $f ( x ) = x ^ { 3 } + 2 x ^ { 2 } - 6 x + 8$

Multiple Choice

Find all the zeros (real and complex) of the function.
- $f ( x ) = x ^ { 3 } + 2 x ^ { 2 } - 6 x + 8$

A) -4, 4
B) $1 + \mathrm { i } , 1 - \mathrm { i } , - 4$
C) $1 + i , 1 - i , 4$
D) $1 - \mathrm { i } , 4 \mathrm { i }$