Four Closed Surfaces Are Shown, Each with Circular Top and Bottom

Multiple Choice

Four closed surfaces are shown, each with circular top and bottom faces and curved sides. The areas A_top and A_bot of the top and bottom faces and the magnitudes B_top and B_bot of the uniform magnetic fields through the top and bottom faces are given. The fields are perpendicular to the faces and are either inward or outward. Rank the surfaces according to the magnitude of the magnetic flux through the curved sides, least to greatest.

A) 1, 2, 3, 4
B) 3, 4, 1, 2
C) 1, 2, 4, 3
D) 4, 3, 2, 1
E) 2, 1, 4, 3