The Center and Radius of the Sphere $x ^ { 2 } + y ^ { 2 } + z ^ { 2 } + 2 x - 2 y = 2$

Multiple Choice

The center and radius of the sphere $x ^ { 2 } + y ^ { 2 } + z ^ { 2 } + 2 x - 2 y = 2$ are

A) $( 2 , - 2,0 ) ; 2$
B) $( 1 , - 1,0 ) ; 1$
C) $( - 1,1,0 ) ; 2$
D) $( 1 , - 1,0 ) ; 2$
E) $( - 2,2,0 ) ; 2$