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: Baltusrol Course lies in which US state?

Answer: baltusrol golf club


Question: The site of the 1461 Battle of Mortimer's Cross lies in which English county?

Answer: battle of mortimer's cross


Question: In Greek mythology who was the sister of Helen and wife of Agamemnon?

Answer:
agamemnon