There are three blocks, A, B and C. A big blue circle, one big blue square and a big yellow square are in block A. To the right of and below the big yellow square is the big blue circle. The big blue square is touching the bottom edge of this block. It is to the left of the big yellow square. Block B is below block A. It has one medium black circle, one small yellow square and a big black square. Near to, above and to the left of the big black square there is the medium black circle. The big black square is touching the bottom edge of this block. Above block A there is block C. It has one medium black circle, one big yellow square and one small yellow circle. The medium black circle is below and to the right of the small yellow circle. The big yellow square is to the right of and near to the small yellow circle. The small yellow circle is touching the left edge of this block.
What is above the big blue square? a medium black circle or a big black square?
medium black circle  big black square  both of them none of them