There are three blocks, A, B and C. Block B is above blocks A and C. Block A contains a medium blue square. Block B has a medium blue square and one medium yellow square. This block also has a medium black square. It is below the medium yellow square. The medium blue square is touching the bottom edge of this block. It is below the medium black square and the medium yellow square. Block C contains a medium yellow square and one medium black square. Below the medium black square there is the medium yellow 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