There are three blocks. We call them A, B and C. Block A is to the left of C and block C is to the right of B. Block A contains a medium black square. Below a medium yellow square is the medium black square. Block B has one medium yellow square. This block also contains one medium black square. The medium black square is below the medium yellow square. Block C contains one medium black square.
Which object is to the left of a medium black square? the medium yellow square which is in block A or the medium yellow square that is in block B?
the medium yellow square  which is in block A the medium yellow square  that is in block B both of them none of them