There are three blocks, A, B and C. There are one medium blue circle, a big black circle and a small yellow square in block A. The medium blue circle is below and to the left of the small yellow square. The big black circle is below the small yellow square. Block B is below block A. It contains one big black triangle. A big blue triangle is to the left of the big black triangle. To the left of block A there is block C with one medium black circle in it.
What is to the left of the medium blue circle? a medium black circle or a big black circle?
medium black circle  big black circle  both of them none of them