Rewrite the Quadratic Function in Standard Form by Completing the Square

Multiple Choice

Rewrite the quadratic function in standard form by completing the square.
- $$f ( x ) = x ^ { 2 } - 8 x$$

A) $f ( x ) = ( x + 8 ) ^ { 2 } - 8$
B) $f ( x ) = ( x + 4 ) ^ { 2 } - 4$
C) $f ( x ) = ( x - 4 ) ^ { 2 } - 16$
D) $f ( x ) = ( x - 8 ) ^ { 2 } - 64$