Five walls of a house have different surface areas, insulation materials, and insulation thicknesses. Rank them in order of the rate of heat flow through the wall, greatest to smallest. Assume the same indoor and outdoor temperatures for each wall.

(a) Area = 120 m²; 10 cm thickness of insulation with thermal conductivity 0.030 W/(m·K)
(b) Area = 120 m²; 15 cm thickness of insulation with thermal conductivity 0.045 W/(m·K)
(c) Area = 180 m²; 10 cm thickness of insulation with thermal conductivity 0.045 W/(m·K)
(d) Area = 120 m²; 10 cm thickness of insulation with thermal conductivity 0.045 W/(m·K)
(e) Area = 180 m²; 15 cm thickness of insulation with thermal conductivity 0.030 W/(m·K)