We have three blocks. Lets call them A, B and C. Block A contains two medium black squares. Medium black square number one is below medium black square number two. This block also has a medium yellow square. The medium yellow square is below medium black square number one and medium black square number two. Block B is above block A. It has one medium blue square. To the right of block A there is block C which has one medium black square.
What is below the blue thing? a medium black square that is in block C or a medium black square number one?
medium black square  that is in block C medium black square  number one both of them none of them