There are three blocks. We call them A, B and C. Block C is above and A is below B. Block A contains one medium black triangle. A big black triangle is also touching the right edge of this block. The medium black triangle is to the left of and below the big black triangle. One small yellow triangle is also in this block. The medium black triangle is touching the bottom edge of this block. The small yellow triangle is to the left of a medium black square and the big black triangle. Block B contains one medium yellow circle. And block C has one small black square. A small blue square is above and to the right of the small black square. The small black square is touching the bottom edge of this block.
What is above the small yellow triangle? a medium black square or a small blue square?
medium black square  small blue square  both of them none of them