When confronted with algebra in Quantitative Comparisons, attempt to solve algebraically for maximum efficiency. If 720 cents can buy 72 bananas, then each banana costs 720 ÷ 72 = 10 cents.

Then, if a banana were to cost 9 cents, 720 cents could buy 720 ÷ 9 = 80 bananas, which in turn means that x = 80 - 72 = 8. So, Quantity A = 8 x 2 = 16.

Finally, is a banana were to cost 8 cents, 720 cents could buy 720 ÷ 8 = 90 bananas, which in turn means that y = 90 - 72 = 18. So, Quantity B = 18.

Select Choice B.