For a real signal, which of the following is/are valid power spectral density/densities?

The frequency response H(f) of a linear time-invariant system has magnitude as shown in the figure.

Statement I : The system is necessarily a pure delay system for inputs which are bandlimited to $$-$$$$\alpha$$ $$\le$$ f $$\le$$ $$\alpha$$.

Statement II : For any wide-sense stationary input process with power spectral density S_X(f), the output power spectral density S_Y(f) obeys S_Y(f) = S_X(f) for $$-$$$$\alpha$$ $$\le$$ f $$\le$$ $$\alpha$$.

Which one of the following combinations is true?

The autocorrelation function $R_X(\tau)$ of a wide-sense stationary random process $X(t)$ is shown in the figure.

$$ \text { The average power of } X(t) \text { is ___________} $$

The random variable

$$ Y=\int_{-\infty}^{\infty} W(t) \phi(t) d t, \quad \text { where } \phi(t)=\left\{\begin{array}{cc} 1, & 5 \leq t \leq 7 \\ 0, & \text { otherwise } \end{array}\right. $$

and $W(t)$ is a real white Gaussian noise process with two-sided power spectral density $S_W(f)=3 \mathrm{~W} / \mathrm{Hz}$, for all $f$. The variance of $Y$ is $\_\_\_\_$ .