Which one of the following statements is NOT TRUE for a continuous time causal and stable LTI system?

For a periodic signal the $$v\left(t\right)=30\sin100t\;+\;10\cos300t\;+\;6\sin\left(500t\;+\;\frac{\mathrm\pi}4\right)$$ fundamental frequency in radians/s is

The impulse response of a system is h(t) = tu(t). For an input u(t − 1), the output is

Assuming zero initial condition, the response y(t) of the system given below to a unit step input u(t) is