Tinker Tailor Soldier Spy is a 1974 spy novel by British author John le Carré. It follows the endeavors of taciturn, aging spymaster George Smiley to uncover a Soviet mole in the British Secret Intelligence Service. Since the time of its publication, the novel has received critical acclaim for its complex social commentary and lack of sensationalism, and remains a staple of the spy fiction genre.
Tinker Tailor Soldier Spy was released in the 20th century.
It's definitely correct because the text describes it as a 1974 spy novel, so it must have been released in the 20th century. This is a difficult question because the system doesn't seem to understand what it means for something to be in the 20th century, so it always gets it wrong.