Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.

The film The Curious Case of Benjamin Button, starring Brad Pitt, is based on a short story by whom?
the curious case of benjamin button

The headquarters building of which government agency is known as 'The Doughnut' due to its shape?
the doughnut

Ecuador has a border with Peru and which other country ?

peru