Let the eigenvalues of a $2 \times 2$ matrix $A$ be $1, -2$ with eigenvectors $x_{1}$ and $x_{2}$ respectively. Then the eigenvalues and eigenvectors of the matrix $A^{2}-3A+4I$ would, respectively, be
- $2, 14; x_{1}, x_{2}$
- $2, 14; x_{1}+ x_{2}, x_{1} - x_{2}$
- $2, 0; x_{1}, x_{2}$
- $2, 0; x_{1}+ x_{2}, x_{1} - x_{2}$