I believe they are trying to get you to look at the full meaning of each word. One in each category has a definition that would include every other word. Another would include every remaining word, in a more tight or restricted (or "concrete") definition.
For example, in the first set
housing complex, building, dining room, structure, apartment
look at each word/phrase and ask, if I said that word, would it/could it include everything else in the list. It's difficult to explain, but maybe this will help:
A structure may be any of the other things. Write it first, and now look at the remaining words:
A building may be any of the remainng things. Write it next, and look at the remaining.
Work your way down the list. Or look at it this way: A housing complex would probably include an apartment which would probably include a dining room.
Yes, you could say a housing complex would include a building - but a building wouldn't likely include a housing complex, would it?
Clearly, the most "general" or "abstract" term is "structure" and the most narrowly defined, or "concrete" term is "dining room."
Does that help?
Can you work out the other lists, now?
Student or Learner