This $3\times 3$ card is shown four times. Three of the panels are images of the card in a mirror placed along one of its sides or diagonals. Which panel is NOT?

(c) is the image in a mirror at the side, (d) in a mirror at the top or bottom, and (a) in a mirror along the diagonal from the bottom-left to the top-right corner (the blue square jumps to the bottom-right). (b) is the card turned half-way round; in it the blue square and the orange half-square have swapped corners in a way no single mirror gives.