A matrix has eigenvalues $–1$ and $–2$. The corresponding eigenvectors are $\begin{vmatrix} 1\\-1 \end{vmatrix}$ and $\begin{vmatrix} 1\\-2 \end{vmatrix}$ respectively. The matrix is
1. $\begin{vmatrix} 1 & 1\\ -1 & -2 \end{vmatrix}$
2. $\begin{vmatrix} 1 & 2\\ -2 & 4 \end{vmatrix}$
3. $\begin{vmatrix} -1 & 0\\ 0 & -2 \end{vmatrix}$
4. $\begin{vmatrix} 0& 1\\ -2 & 3 \end{vmatrix}$