Pictures (i) to (iii) show one colour cube. Which of the cubes (a) to (d) can NOT be the same cube?

(iii) shows green, violet and blue at one corner. (c) shows the same three colours but in the opposite order round the corner, so it is a mirror image. (a), (b) and (d) are the cube of (i)–(iii) turned to new positions.