There are three blocks. Lets call them A, B and C. There is a medium yellow square in block A. It also has a small yellow circle. Near to and above the medium yellow square is the small yellow circle. The medium yellow square is touching the bottom edge of this block. Above block A is block B with one big blue triangle and a medium black square in it. It also contains a big black square and a medium black triangle. The big black square is above the medium black square. The big blue triangle is below, to the right of and near to the medium black square. The big black square is to the left of, below and near to the medium black triangle. Finally, there is block C. It is below block B. It contains one big blue circle and one small yellow square. The big blue circle is below and to the left of the small yellow square.
What is below the medium black triangle? a big black square or a small yellow square?
big black square  small yellow square  both of them none of them