In the system shown below, $x(t)=(\sin t) u(t)$. In steady-steady-state, the response $y(t)$ will be
- $\frac{1}{\sqrt{2}} \sin \left(t-\frac{\pi}{4}\right)$
- $\frac{1}{\sqrt{2}} \sin \left(t+\frac{\pi}{4}\right)$
- $\frac{1}{\sqrt{2}} e^{-t} \sin t$
- $\sin t-\cos t$