There are three blocks. Lets call them A, B and C. There is a medium black square in block A. Below the medium black square is a medium yellow square. Below block A we have block B with one medium blue square and a medium black square in it. Below the medium black square is the medium blue square. Finally, we have block C which is above block A. It contains two medium black squares. Medium black square number one is touching the bottom edge of this block. It is below medium black square number two.
What is below the thing that is touching the bottom edge of a block? a medium black square which is in block B or a medium black square that is in block A?
medium black square  which is in block B medium black square  that is in block A both of them none of them