Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
--------
Question: With which song did Swedish pop group Abba win the 1974 Eurovision Song Contest?

Answer: abba

Question: Who played the title role in the 1955 film 'Davy Crockett, King Of The Wild Frontier'?

Answer: davy crockett

Question: Which of the following appeared in both the films 'Magnolia' and 'Boogie Nights' Mark Wahlberg, Julianne Moore or Tom Cruise?

Answer:
magnolia