The matrix $\left(\begin{array}{cc}2 & -4 \\ 4 & -2\end{array}\right)$ has
(A) real eigenvalues and eigenvectors
(B) real eigenvalues but complex eigenvectors
(C) complex eigenvalues but real eigenvectors
(D) complex eigenvalues and eigenvectors
The matrix $\left(\begin{array}{cc}2 & -4 \\ 4 & -2\end{array}\right)$ has
(A) real eigenvalues and eigenvectors
(B) real eigenvalues but complex eigenvectors
(C) complex eigenvalues but real eigenvectors
(D) complex eigenvalues and eigenvectors