# 18. A real-valued signal x(t) limited to the f...

18. A real-valued signal x(t) limited to the frequency band |f| ≤ $w\over2$ is passed through a linear time
invariant system whose frequency response is

The output of the system is

(A) x(t+4)

(B) x(t-4)

(C) x(t+2)

(D) x(t-2)

Hint: