Which one of the following CANNOT be the complete housing arrangement for habitats 1 and 2?

I understand that for this game, drawing out the distributions is helpful, but how come it can only be - 2-2-2-1 and 2-2-1-1-1? Couldn't it also be 2-1-2-2-0? and then for this specific question, how did the instructor apply answer D to the 2-2-2-1 distribution if the Habitat 2 is empty? If the others could be true, and the correct answer cannot be true, wouldn't the distribution for answer A be 2-1-2-2-0? I can clarify my question if this isn't clear. Thank you!