What is the best meaning of the phrase at the entrance to auschwitz, “arbeit macht frei? ”

“no man is free”
“only the good are free”
“work sets you free”
“education makes you free”

Work sets you free.

The best meaning of the phrase at the entrance to Auschwitz is "work sets you free." At Auschwitz the prisoners were made to work constantly under terrible conditions. The only hope they had was the hope they'd be set free. Unfortunately, this became true of Auschwitz many prisoners were set free after doing laborious work. They were freed from life because the work and conditions were so strenuous, they died. The prisoners at Auschwitz were not given an education. Prisoners arriving under a sign that says "No man is free" may have been less likely to stay at the camp peacefully.

the answer is:

when will (v) the books (n) be (v) due?

nouns refer to people (other than pronouns), places and things, whereas verbs describe actions and are usually part of the predicate of a sentence. finally, pronouns can work as nouns and identify the participants in speech.

in the example sentence, "will" is a verb part or auxiliary verb, "be" is an infinitive verb and "books" is a plural noun.

i’m confused as to what your asking ?