Correct Answer - Option 3 :
\(\frac{{{e^{ - 2s}}}}{s}\)
\(y\left( t \right) = \mathop \smallint \limits_0^t x\left( {\tau - 2} \right)\;d\tau \)
Transfer function is the impulse response So, the input is impulse function, i.e. δ(t)
\(h\left( t \right) = \mathop \smallint \limits_0^t \delta \left( {\tau - 2} \right)d\tau\)
⇒ h(t) = u(t-2)
By applying Laplace transform
\(H\left( s \right) = \frac{{{e^{ - 2s}}}}{s}\)