We have three blocks, A, B and C. There is a medium blue square in block A. This block also has a medium black square. The medium blue square is touching the bottom edge of this block. It is below the medium black square. Block B is below block A. It contains a medium yellow square. Below block B there is block C with a medium blue square and one medium yellow square in it. Below the medium yellow square there is the medium blue square.
What is below the object that is touching the bottom edge of a block? a medium yellow square or a medium black square?
medium yellow square  medium black square  both of them none of them