We have three blocks, A, B and C. Block A contains two medium black squares. Medium black square number one is below medium black square number two. Then, there is block B. It has one medium yellow square. Block C is above block A and below block B. It has two medium blue squares. Medium blue square number one is below medium blue square number two. This block also contains one medium black square. Below medium blue square number one and medium blue square number two there is the medium black square.
What is below the object that is touching the bottom edge of a block? a medium black square or a yellow thing?
medium black square  yellow thing both of them none of them