In a work of fiction, where is the best place to look for supporting details that indicate the theme?

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."

It's to know your purpose before you read something because a purpose can:

What makes the literal, word-for-word translation of the metamorphosis hard to read?