Which of the following describes a "notch filter"?

A) A filter that passes all frequencies except for a narrow range

B) A filter that only passes low frequencies

C) A filter that attenuates high frequencies

D) A filter that amplifies all frequencies equally

Answer: A) A filter that passes all frequencies except for a narrow range

Explanation: A notch filter (or band-stop filter) is designed to attenuate signals within a very narrow band of frequencies while allowing all other frequencies to pass, effectively removing specific interference or noise.