Solve the Nonlinear System of Equations for Real Solutions $\left\{ \begin{aligned}x ^ { 2 } + y ^ { 2 } & = 4 \\y & = \frac { 1 } { 2 } x ^ { 2 } - 2\end{aligned} \right.$

Multiple Choice

Solve the nonlinear system of equations for real solutions.
- $\left\{ \begin{aligned}x ^ { 2 } + y ^ { 2 } & = 4 \\y & = \frac { 1 } { 2 } x ^ { 2 } - 2\end{aligned} \right.$

A) $( - 2,0 ) , ( 2,0 )$
B) $( - 2,0 ) , ( 2,0 ) , ( 0,2 )$
C) $( - 2,0 ) , ( 0,2 ) , ( 0 , - 2 )$
D) $( - 2,0 ) , ( 2,0 ) , ( 0 , - 2 )$