Which of the following is true about the frequency response of a system?

A) It only applies to continuous-time systems

B) It describes how the system responds to different frequencies

C) It is always linear

D) It does not change with time

Answer: B) It describes how the system responds to different frequencies

Explanation: The frequency response of a system characterizes how the system behaves at different frequencies, including gain and phase shift. It is a crucial aspect of understanding both analog and digital systems.