There are three blocks. We call them A, B and C. Block C is above A and block B is above C. Block A has two medium black squares. Medium black square number one is below medium black square number two. A medium blue square is also touching the bottom edge of this block. The medium blue square is below medium black square number two and medium black square number one. Block B has a medium blue square. And block C has a medium yellow square.
What is above the thing that is touching the bottom edge of a block? a medium black square or a medium yellow square?
medium black square  medium yellow square  both of them none of them