Find a Polynomial of Least Degree with Only Real Coefficients $$2 + i , 4$$

Multiple Choice

Find a polynomial of least degree with only real coefficients and having the given zeros.
- $$2 + i , 4$$

A) $f ( x ) = x ^ { 3 } + 8 x ^ { 2 } + 21 x + 20$
B) $f ( x ) = x ^ { 3 } + 9 x ^ { 2 } + 20 x + 20$
C) $f ( x ) = x ^ { 3 } - 8 x ^ { 2 } + 21 x - 20$
D) $f ( x ) = x ^ { 3 } - 4 x ^ { 2 } - ( 3 - 4 i ) x + 12 + 16 i$