The diagrams show three circuits consisting of concentric circular arcs (either half or quarter circles of radii r, 2r, and 3r) and radial lengths The circuits carry the same current: Rank them according to the magnitudes of the magnetic fields they produce at C, least to greatest;
A) 1,2,3 B) 3,2,1 C) 1,3,2 D) 2,3,1
E) 2,1,3