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: SCIENCE & NATURE 
Clue: Developed by astronomer A.E. Douglass, dendrochronology determines age in this way
counting tree rings

Category: HOW DO THEY WORK? 
Clue: Many car salesman work on "straight" this, though you're better off buying from one who's on salary
commission

Category: U.S. CITIES 
Clue: Granite works sprung up in & around this state capital using stone from Barre, a few miles away

montpelier