Which term best describes the International Standard Book Number used for identification?

• A. International Standard Book Number for identification
• B. Internet Standard Book Number
• C. International System for Books and Notation
• D. International Standard Bookmark Number

Answer: (A)

An ISBN is a standardized, globally used identifier for books, enabling precise identification of a title and edition across catalogs, libraries, and retailers. The best answer names the term as International Standard Book Number along with its purpose, which is to identify books accurately. That option aligns with the established designation used worldwide to identify books. The other terms describe concepts that don’t exist in publishing—Internet Standard Book Number, an unrelated system; International System for Books and Notation, not a real standard; and International Standard Bookmark Number, which confuses bookmarks with book identifiers.