A card with a grid of three rows and four columns is first seen in the dashed mirror, and that mirror image is then seen in the water below. Which panel shows the final image?

The mirror swaps the columns and the water swaps the rows, so together every item goes to the diagonally opposite cell: the blue cell moves to the bottom-right, the yellow cell to the top-left, the dot to the bottom row, and the corner triangle and the arrow are turned through half a turn: (a). (b) and (c) stop after one reflection, and (d) has the arrow moved but not turned.