Match the polynomial function to its correct roots

Place the letter of the list of correct roots next to each function listed below:

 1. $f(x)=x^4 - 8x^3 + 24x^2 - 32x + 16$
 2. $f(x)=x^4 + 4x^3 - 16x - 16$
 3. $f(x)=x^4+8x^3+24x^2+32x+16$
 4. $f(x)=x^4+4x^3+8x^2+16x+16$

A. $x=2, 2, 2, 2$
B. $x=-2,-2,-2,-2$
C. $x=-2, -2, -2, 2$
D. $x=+2i,-2i,-2,-2$