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