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: HOMOPHONES 
Clue: A caustic substance in soap, or an untruth

Answer: lye/lie


Question: Category: TRAVEL U.S.A. 
Clue: Caligula would love the Caligula Suite in the Emperors Complex of this Las Vegas hotel

Answer: caesars palace


Question: Category: -OLOGIES 
Clue: It's the science & application of X-rays

Answer:
roentgenology