Hệ phương trình \(\left\{ \begin{array}{l}x + y + xy = 11\\{x^2} + {y^2} + 3(x + y) = 28\end{array} \right.

A. \(\left( {3;2} \right),\left( {2;3} \right).\)

B. \(\left( { - 3; - 7} \right),\left( { - 7; - 3} \right).\)

C. \(\left( {3;2} \right);\left( { - 3; - 7} \right).\)

D. \(\left( {3;2} \right),\left( {2;3} \right),\left( { - 3; - 7} \right),\left( { - 7; - 3} \right).\)