There are three blocks. We call them A, B and C. Block A contains a small blue square. Above block A there is block B which contains a small yellow triangle, one big black circle and one medium yellow circle. Below the medium yellow circle and the big black circle is the small yellow triangle. Finally, we have block C above block A. It has one small blue triangle. This block also contains a medium yellow triangle. Far from and above the small blue triangle is the medium yellow triangle.
Which object is above a small blue thing? the big black circle or the medium yellow circle?
the big black circle  the medium yellow circle  both of them none of them