Find the Center and the Radius of the Sphere That $$x ^ { 2 } + y ^ { 2 } + z ^ { 2 } - 4 x + 8 y = 0$$

Multiple Choice

Find the center and the radius of the sphere that has the given equation.
$$x ^ { 2 } + y ^ { 2 } + z ^ { 2 } - 4 x + 8 y = 0$$

A) $( 2 , - 4,0 ) , 2 \sqrt { 5 }$
B) $( - 2,4,0 ) , 20$
C) $( - 2,4,0 ) , 2 \sqrt { 5 }$
D) $( 2 , - 4,0 ) , 20$