What a literary critic determine the stories theme?

What sentence correctly uses it’s underlined relative pronoun?

Which detail from the text best demonstrates the effect of totalitarianism on the animals? "progress was made in the dry frosty weather that followed." "it had been decided to build the walls three feet thick." "they were always cold, and usually hungry as well." "for a long time the quarry was full of snowdrifts and nothing could be done."

According to aristotle, what is an "artistic" proof?