The unit impulse response of a unity feedback control system is given by;
\[
c(t)=-t e^{-t}+2 e^{-t},(t \geq 0)
\]
The open loop transfer function is equal to
(a) \(\frac{(s+1)}{(s+2)^{2}}\)
(b) \(\frac{2 s+1}{s^{2}}\)
(c) \(\frac{s+1}{(s+1)^{2}}\)
(d) \(\frac{s+1}{s^{2}}\)