Mr. Webb has 16 feet of fencing. He wants to use all of the
 fencing to enclose a rectangular flower bed. The graph below
 shows how the area of the flower bed depends on the length
 of one of its sides.
 16
 14
 12
 10
 Area (square feet)
 8
 Length (feet)
 What side length will give the flower bed the maximum area?
 A 16 ft
 B 4 ft
 8 ft D 2 ft