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.

Category: LARGE EQUIPMENT 
Clue: For smooth travel, ballast tampers & ballast regulators keep the gravel at the right level among these
railroad tracks

Category: HEY, "D.J." 
Clue: James Buchanan Brady's gem of a moniker
diamond jim

Category: MY SPICE 
Clue: In a sushi bar, you will likely be offered some pickled this so you can cleanse your palate between bites

ginger