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.

[Q]: Category: POETIC LINES 
Clue: In a famous poem, this character asks, "If I can rid your town of rats will you give me a thousand guilders?"
[A]: the pied piper


[Q]: Category: MY CHARLEMAGNE MAN 
Clue: For 46 years Charlemagne was the king of these people who gave their name to a country
[A]: the franks


[Q]: Category: SECOND LETTER "X" 
Clue: It's a universally accepted principle or rule
[A]:
an axiom