Respuesta :
Hey there!!
We group terms which contain the same variable.
Given :-
... 2xy - 9cx - 18cy + 81c²
After grouping :-
... 2xy - 18cy - 9cx + 81c²
Picking the common terms :-
... 2y ( x - 9c ) - 9c ( x - 9c )
... ( 2y - 9c ) ( x - 9c )
Hence, the answer is option ( B )
Hope it helps!