There are three blocks. We call them A, B and C. Block B is above A. Block A is above C. Block A has a small yellow triangle. Block B contains a small black triangle. Block C contains one small blue square, a medium yellow square and one medium blue triangle. The medium yellow square is below a big black triangle and the medium blue triangle. One medium black triangle is also in this block. This shape is to the left of and above the big black triangle.
Which object is below a medium blue triangle? the small black triangle or the medium yellow square?
the small black triangle  the medium yellow square  both of them none of them