Let us check each Option :
[tex]\mathsf{First\;Option : \left(\dfrac{m + 9}{m - 9}\right)\left(\dfrac{m + 9}{m - 9}\right)}[/tex]
[tex]\mathsf{\implies \left(\dfrac{m + 9}{m - 9}\right)^2\;\neq\;1}[/tex]
[tex]\mathsf{Second\;Option : \left(\dfrac{m + 9}{m - 9}\right)\left(\dfrac{m - 9}{m + 9}\right)}[/tex]
[tex]\mathsf{\implies 1}[/tex]
[tex]\mathsf{Third\;Option : \left(\dfrac{m + 9}{m - 9}\right)\left(\dfrac{9 + m}{9 - m}\right)}[/tex]
[tex]\mathsf{\implies \left(\dfrac{m + 9}{m - 9}\right)\left(\dfrac{m + 9}{-(m - 9)}\right)}[/tex]
[tex]\mathsf{\implies-\left(\dfrac{m + 9}{m - 9}\right)\left(\dfrac{m + 9}{m - 9}\right)}[/tex]
[tex]\mathsf{\implies-\left(\dfrac{m + 9}{m - 9}\right)^2\;\neq\;1}[/tex]
[tex]\mathsf{Fourth\;Option : \left(\dfrac{m + 9}{m - 9}\right)\left(\dfrac{9 - m}{9 + m}\right)}[/tex]
[tex]\mathsf{\implies \left(\dfrac{m + 9}{m - 9}\right)\left(\dfrac{-(m - 9)}{9 + m}\right)}[/tex]
[tex]\mathsf{\implies -\left(\dfrac{m + 9}{m - 9}\right)\left(\dfrac{m - 9}{9 + m}\right)}[/tex]
[tex]\mathsf{\implies -1\;\neq\;1}[/tex]
Answer : Option (2)
