A rectangular field is to be enclosed on four sides with a fence. Fencing costs $4 per foot for two opposite sides, and $5 per foot for the other two sides. Find the dimensions of the field of area 880 ft^2 that would be the cheapest to enclose. Round to the nearest tenth.
a) Length = 20.9 ft, Width = 42.2 ft
b) Length = 22.1 ft, Width = 39.8 ft
c) Length = 24.5 ft, Width = 35.9 ft
d) Length = 26.3 ft, Width = 33.4 ft