There are three blocks. We call them A, B and C. There is a medium black square in block A. Below block A we have block B with two medium blue squares in it. Below medium blue square number two there is medium blue square number one. Below medium blue square number two and medium blue square number one there is a medium yellow square. Below block B there is block C which has a medium yellow square.
Which object is above a medium yellow square? medium blue square number one or medium blue square number two?
medium blue square  number one medium blue square  number two both of them none of them