Open Loop Control System

Q. The unit impulse response of a unit feedback control system is given by: $c\left(t\right)=-t{e}^{-t}+2e^{-t},(t\ge 0)$ the open loop transfer funciton is equal to

1. $\frac{s+1}{(s+2{)}^2}$
2. $\frac{2s+1}{s^2}$
3. $\frac{s+1}{(s+1{)}^2}$
4. $\frac{s+1}{s^2}$