The answer is A. Greatest common factor is 8xy because of the gcf and wat the equation has in common, xy. Then you are here- 8xy(?-?). Now, you have to find what's in the parenthesis. So, what number multiplied by 8xy gives you 32, you already have your variables, is 4. 8xy(4-?). Then what number multiplied by 8xy gives you -56z? It's -7z. So u r done. 8xy(4-7z).