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.

Category: HEAVY MACHINERY 
Clue: By definition it's a machine that gives a surface an even degree of slope
grader

Category: MILITARY MATTERS 
Clue: Major Esterhazy was probably the real spy for the Germans in this French "affair" that began in 1894
dreyfus affair

Category: CONTEMPORARY AUTHORS 
Clue: This "Bonfire Of The Vanities" author once tried out as a pitcher for the New York Giants

tom wolfe