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

[EX Q]: In which opera does a hunchback jester help his master, the Duke of Mantua, to seduce the daughter of a courtier?
[EX A]: duke of mantua

[EX Q]: Who released the albums Sentimental Journey, Goodnight Vienna, Bad Boy, Old Wave and Vertical Man between 1970 and 1999?
[EX A]: vertical man

[EX Q]: Who plays the title role in the US television series 'Buffy the Vampire Slayer'?
[EX A]:
buffy the vampire slayer