There are three blocks. We call them A, B and C. Block A contains a medium yellow square. Above block A we have block B with one medium yellow square and a medium black square in it. The medium yellow square is below the medium black square. Above block B there is block C. It contains a medium black square and one medium yellow square. The medium black square is touching the bottom edge of this block. It is below the medium yellow square.
Which object is below a medium black square? the medium yellow square which is in block B or the medium yellow square that is in block C?
the medium yellow square  which is in block B the medium yellow square  that is in block C both of them none of them