If A= ( frac{- _1^2+ _u _l}{ _1 ( _u- _l)} ) and B= ( frac{ _2^2- _u _l}{ _2 ( _u- _l)} ), then which of the following is the backward design equation for a low pass-to-band pass transformation?

• A. _S=|B|
• B. _S=|A|
• C. _S=Max{|A|,|B|}
• D. _S=Min{|A|,|B|}