Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
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Question: Who painted The Card Players, at Feb 2012 the most expensive artwork in the world?

Answer: the card players

Question: 'Edward Lewis' and 'Vivian Ward' were the principal characters in which popular 1990 film?

Answer: edward lewis

Question: William Lamb was the family name of which 19th century titled British Prime Minister?

Answer:
prime minister of the united kingdom