Fiona is making a box to hold firewood cut to 20-inch lengths. The box has to be 2 feet wide to accommodate the length of the wood pieces. Fiona wants the length to be 7 feet longer than the height. The graph models the possible volume (y) of Fiona’s box determined by its length (x). Which value of x makes sense for the length of Fiona’s box? x < 7 x > 0 x > 3.5 x > 7