A : B :: C : ? Pick the answer figure that completes the analogy.

In A a big blue circle holds a small yellow square; in B the yellow square has become the big outer shape and the blue circle the small inner one — the two shapes change places and each keeps its own colour. So C's small red triangle becomes the big outer shape and the violet hexagon goes inside: (c). (a) swaps the shapes but not their colours, (b) swaps only the colours and (d) forgets to put the hexagon inside.