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 consistency, answers should be in all lower cased letters.

Q: Category: COLLEGE SPORTS 
Clue: 2 college players have rushed for more than 2,300 yards in a season: Barry Sanders & this USC back, later a Raider

A: marcus allen
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Q: Category: LARGE EQUIPMENT 
Clue: For smooth travel, ballast tampers & ballast regulators keep the gravel at the right level among these

A: railroad tracks
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Q: Category: TECHWORD MASH-UP 
Clue: ZQ47J9R is this type of password, from the 2 types of symbols it contains

A:
alphanumeric
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