There are three blocks, A, B and C. Block A contains a medium blue square. Above block A there is block B. It contains two medium black squares. Medium black square number one is below medium black square number two. Above block B there is block C. It contains one medium blue square and a medium yellow square. The medium blue square is below the medium yellow square.
Which object is above a medium blue square? medium black square number two or medium black square number one?
medium black square  number two medium black square  number one both of them none of them