This variation is a curious case of a defense that is known equally by two names: some call it the Kan, some call it the Paulsen. It's a daring choice for someone who just needs a draw, but Carlsen knows what he's doing. He doesn't play it too often, although he has tried it a few times.
1. e2e4  1... c7c5  2. g1f3  2... e7e6  3. d2d4  3... c5d4  4. f3d4 