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 married the woman who was to become Queen Beatrix of the Netherlands, on 10 March 1966?

Answer: beatrix


Question: What's the name of Doctor Who's home planet ?

Answer: doctor who


Question: 1936 saw Ty Cobb, Babe Ruth, Honus Wagner, Christy Mathewson and Walter Johnson the first inductees into what?

Answer:
babe ruth