Three of the panels show this toy rocket in a mirror placed on some side of it (upright, flat or slanting). Which panel can NOT be a mirror image of the rocket?

Look at the porthole (near the nose) and the dot (near the tail, above the body). (a) is the image in an upright mirror, (b) in a flat mirror, and (d) in a mirror along a diagonal. (c) is the rocket turned through $90^{\circ }$: turning keeps the dot on the same side of the body as seen from the nose, which no mirror can do.