What is the z-transform of the first backward difference equation of y

1.	What is the z-transform of the first backward difference equation of y(n)?
A.	( frac{1+z^{-1}}{T} ) Y(z)
B.	( frac{1-z^{-1}}{T} ) Y(z)
C.	( frac{1+z^1}{T} ) Y(z)
D.	None of the mentioned
Answer» C. ( frac{1+z^1}{T} ) Y(z)

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