You can suspect (D) because there is a range of possible values for the variables. In Quantity A, you have the volume of a rectangular solid with length 5 feet, width 4 feet, and height x feet. The formula is length times width times height, so the volume is 5 times 4 times x, or 20x. The volume of Quantity B is therefore 10 times 8 times y, or 80y. If 4 < x < 6, then the range of values for Quantity A is 80 < V < 120. If 1 < y < 2, then the range of values for Quantity B is 80 < V < 160. Since the two ranges overlap, it’s possible that the two quantities are equal or that one is greater than the other. So, the correct answer is (D).