Answer:
The third one
Explanation:
Since this is looking down on the cubes from above, I feel it is safe to assume that it is the third one.
From left to right, top to bottom:
3, 2, 2
2, 2, 1
2, 2, 1
We can see that all but 3 layers are 2 blocks high. The 3 block area is the top left corner, since it is 1 block higher than the 2 block areas, and the 1 block areas are the middle right and the bottom right areas.