Six hollow cylinders having diameters d and heights H are filled with water. The cylinders all have a hole drilled in their sides; the holes are all the same size and are all located at the same height above the bases of the cylinders. The holes are plugged with rubber stoppers. The values of d and H for the six cylinders are provided. Rank the combinations according to the pressure exerted by the water on the stopper from largest to smallest. If two (or more) combinations yield the same pressure, give them the same ranking. (Use only ">" or "=" symbols. Do not include any parentheses around the letters or symbols.)

a. d = 0.35 m; H = 0.72 m

b. d = 0.56 m; H = 0.60 m

c. d = 0.35 m; H = 0.42 m

d.d = 0.70 m; H = 0.42 m

e.d = 0.28 m; H = 0.60 m

f. d = 0.35 m; H = 0.48 m