Which of the following is/are not a property/properties power spectral density function Sx(ω)?

• A. Sx(ω) is real function of ω
• B. Sx(ω) is a even function of ω
• C. Sx(ω) is non-positive function of ωSx(ω) ≤ 0 for all ω
• D. All of the above