What is the expression for low pass signal component us(t) that can be expressed in terms of samples of the bandpass signal?

• A. ( sum_{n=- }^ (-1)^{n+r+1} x(2nT^{ }-T^{ }) frac{sin u2061( /(2T^{ })) (t-2nT^{ }+T^{ })}{( /(2T^{ }))(t-2nT^{ }+T^{ })} )
• B. ( sum_{n=- }^ (-1)^n x(2nT^{ }) frac{sin u2061( /(2T^{ })) (t-2nT^{ })}{( /(2T^{ }))(t-2nT^{ })} )
• C. All of the mentioned
• D. None of the mentioned