You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For simplicity, answers should be in all lower cased letters.
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Question: Category: WORLD LEADERS 
Clue: At his 1994 inaugural, he called for "a rainbow nation at peace with itself and the world"

Answer: nelson mandela


Question: Category: AMERICAN LITERATURE 
Clue: Controversial even when serialized in the "National Era", it sold over 300,000 copies in book form in 1852

Answer: uncle tom\'s cabin


Question: Category: ROYALTY 
Clue: This man whose titles include Baron Greenwich is, like his wife, a great-great-grandchild of Queen Victoria

Answer:
prince philip