The decay ratio for a system having complex conjugate poles as  $\left ( -\frac{1}{10}+j\frac{2}{15} \right )$ and $\left ( -\frac{1}{10}-j\frac{2}{15} \right )$ is

1. $7\times 10^{-1}$
2. $8\times 10^{-2}$
3. $9\times 10^{-3}$
4. $10\times 10^{-4}$