The state variable description of a linear autonomous system is \(\dot{x}=\mathrm{A} x\) where \(x\) is a state vector and

\[
A=\left[\begin{array}{ll}
0 & 2 \\
2 & 0
\end{array}ight]
\]

The poles of the system are located at
(a) -2 and +2
(b) -2 and -2
(c) \(-2 j\) and \(+2 j\)
(d) +2 and +2