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: Richard Block and David Quayle founded which British-based DIY retailing company in 1969?

Answer: david quayle


Question: Mar Chiquita (Cordoba) is the largest natural salt lake in which South American country?

Answer: mar chiquita lake


Question: Callisto and Io are moons of which planet?

Answer:
io