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: Name the actress, she died in August 2002, who played the part of 'Madame Edith Artois' in the TV series 'Allo, Allo'?

Answer: edith artois


Question: Who, as the first chairman of the British Rail Board, infamously directed the huge reduction in railway lines across the UK in the 1960s?

Answer: british railways board


Question: Who wrote the 1911 opera 'Der Rosenkavalier'?

Answer:
der rosenkavalier