- "The teachers'" is a possessive noun (plural) showing that the books belong to multiple teachers.- "The teacher's" is a possessive noun (singular) showing that the book belongs to one teacher.Incorrect options:- "The teacher books" lacks possessive form.- "The teachers books" should be "The teachers'" (plural possessive).Additional examples:- Singular possessive: The cat's toy.- Plural possessive: The cats' toys.- Multiple owners: John and Mary's car.- Individual owners: John's and Mary's cars.[tex].[/tex]