We have three blocks. Lets call them A, B and C. A medium yellow square, one medium black square and a big yellow triangle are in block A. Above the medium black square is the medium yellow square. The medium black square is below a medium blue circle and the big yellow triangle. To the right of and near to the big yellow triangle is the medium yellow square. Then, we have block B with one medium black square in it. One big black square is also in this block. To the right of and above the medium black square there is the big black square. Below block B and to the right of block A there is block C. It contains one medium blue triangle.
What is to the left of the medium blue triangle? a big black square or a big yellow triangle?
big black square  big yellow triangle  both of them none of them