Choose the transfer function that best fits the output response to a unit step input change shown in the figure
- $\frac{(\alpha s+1) e^{-\theta s}}{\left(\tau_{1} s+1\right)\left(\tau_{2} s+1\right)^{2}}$
- $\frac{(\alpha s+1) e^{-\theta s}}{\left(\tau_{1} s+1\right)\left(\tau_{2} s+1\right)}$
- $\frac{(\alpha s+1)}{\left(\tau_{1} s+1\right)\left(\tau_{2} s+1\right)^{2}}$
- $\frac{(\alpha s+1)^{2} e^{-\theta s}}{\left(\tau_{1} s+1\right)\left(\tau_{2} s+1\right)^{2}}$
