A $4 \times 4$ matrix $[P]$ is given below

$$[P] = \begin{bmatrix}0 &1 &3 &0 \\-2 &3 &0 &4 \\0 &0 &6 &1 \\0 &0 &1 &6 \end{bmatrix}$$

The eigen values of $[P]$ are

1. $0, 3, 6, 6$
2. $1, 2, 3, 4$
3. $3, 4, 5, 7$
4. $1, 2, 5, 7$