There are three blocks, A, B and C. Block B is above blocks A and C. Block A contains one medium yellow square. Block B contains a medium blue square and one medium black square. The medium blue square is below a medium yellow square and the medium black square. The medium yellow square is below the medium black square. And block C contains a medium black square.
Is there a medium black square below all squares that are below a black square which is in block B?