We have three blocks, A, B and C. There is one medium yellow square in block A. Below block A we have block B which contains one medium black square. Below block A there is block C. It has one medium yellow square and a medium black square. The medium yellow square is below a medium blue square and the medium black square. The medium blue square is below the medium black square.
Which object is below a medium yellow square? the medium black square which is in block B or the medium black square that is in block C?
the medium black square  which is in block B the medium black square  that is in block C both of them none of them