What is the spatial relation betweeen the green block and the red block?
(A) The green block is directly above the red block, and they are in the same stack.
(B) The green block is directly below the red block, and they are in the same stack.
(C) The green block and the red block are at different stacks.
(D) At least one of the green block and the red block does not exist in the presented configurations.