There are two blocks. We call them A and B. Block A has one small blue triangle. To the right of the small blue triangle is a medium black square. Below block A we have block B. It has a medium yellow square, one big black circle and a medium blue square. There is also a big black square in this block. The medium yellow square is above the big black square , the big black circle and the medium blue square.
What is below the medium black square? a big black square or a medium yellow square?
big black square  medium yellow square  both of them none of them