Is "eure Bücher", acceptable also? As in your (plural) books?
Yes.
But if you have the answers, its pointless to argue about what other option it coukd be
Ihre bucher Deine bucher Eure bucher
Isn't "Ihre Bücher" an acceptable alternative to "your books" since it is in the formal tense of "your"?
Yes, will fix. Thank you!