We have three blocks. We call them A, B and C. Block A has one medium black square and a medium blue square. The medium black square is touching the bottom edge of this block. It is below the medium blue square. Below block A is block B. It has two medium black squares. Below medium black square number two there is medium black square number one. Finally, there is block C which is to the left of block B. It has one medium black square and a medium yellow square. Below the medium yellow square is the medium black square.
What is below the yellow thing? a medium blue square or a medium black square?
medium blue square  medium black square  both of them none of them