Pairs of magnets are shown in the diagram. Bar magnets lined up vertically side by side in pairs. The first pair is labeled W with the north pole beside the south pole of the second. The second pair is labeled X and vertical with the north pole of one near the north pole of the other. The third pair is labeled Y with the south pole of one near the north pole of the other. The last pair is labeled Z and are lined up side by side. The south pole of one is beside the north pole of the second. Which pair of magnets is aligned so they will repel each other?