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.

Example Input: Category: THE TITANIC 
Clue: When the RMS Titanic sank in 1912, its cargo included more than 7 million pieces of this, in some 3,400 sacks
Example Output: mail

Example Input: Category: PUBLISHING 
Clue: Founded in 1856, this company introduced a numbering system for U.S. highways in 1917
Example Output: rand mcnally

Example Input: Category: POP SINGERS 
Clue: Charting her 18th No. 1 single in April 2008, she now has more Billboard No. 1 pop hits than any other solo artist
Example Output:
mariah carey