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