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

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

The Bob Dylan songs 'Desolation Row', 'Tombstone Blues' and 'Like A Rolling Stone' featured on which album?
tombstone blues

What was the name of Audrey Hepburn's character in the 1964 film 'My Fair Lady'?
audrey hepburn