Solve the Nonlinear System of Equations for Real Solutions $\left\{ \begin{array} { l } x ^ { 2 } + y ^ { 2 } = 20 \\x ^ { 2 } - y ^ { 2 } = 12\end{array} \right.$

Multiple Choice

Solve the nonlinear system of equations for real solutions.
- $\left\{ \begin{array} { l } x ^ { 2 } + y ^ { 2 } = 20 \\x ^ { 2 } - y ^ { 2 } = 12\end{array} \right.$

A) $( 4,2 ) , ( 2,4 ) , ( - 4 , - 2 ) , ( - 2 , - 4 )$
B) $( - 4 , - 2 ) , ( - 2 , - 4 )$
C) $( 4,2 ) , ( - 4,2 ) , ( 4 , - 2 ) , ( - 4 , - 2 )$
D) $( 4 , - 2 ) , ( 4,2 )$