STC networks can be classified into two categories: low-pass (LP) and high-pass (HP). Then which of the following is true?

• A. hp network passes dc and low frequencies and attenuate high frequency and opposite for lp network
• B. lp network passes dc and low frequencies and attenuate high frequency and opposite for hp network
• C. hp network passes dc and high frequencies and attenuate low frequency and opposite for lp network
• D. lp network passes low frequencies only and attenuate high frequency and opposite for hp network