Mark the correct alternative in the following:

For any two sets A and B, (A B)(B A) =


(AB)(BA)=[AB' ][BA']


=[A(BA' )][B'(BA' )]


=[(AB)(AA' )][(B'B)(B'A' )]


=[(AB)ϕ][ϕ(B'A' )]


=[(AB)][(B'A' )


=[(AB)][(BA)' ]


=(BA)'(AB)


=(AB)(AB)

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