First of all is that singular and is those related to that?
According to a recent poll, owning and living in a freestanding house on its own land is still a goal of a majority of young adults, ( like that of earlier generations.)
Why is that unambigious?
What can that refer to?
- Poll (probably not
So, probably it is goal.
Can you get a grammar book and look up that/this and those/these?
You will be greatly damaged for learning just pieces and not knowing the material soundly. Learning from questions is not the best approach.