(A)
- Stack with red block, orange block, purple block, green block, from bottom to top

(B)
- Stack with green block, purple block, orange block, red block, from bottom to top

(C)
- Stack with red block
- Stack with purple block
- Stack with green block, orange block, from bottom to top

(D)
- Stack with red block
- Stack with green block, orange block, from bottom to top
- Stack with yellow block, blue block, from bottom to top