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.

Q: Category: SCIENCE & NATURE 
Clue: Developed by astronomer A.E. Douglass, dendrochronology determines age in this way

A: counting tree rings
****
Q: Category: HI, I "Q" 
Clue: It's a synonym for idiosyncrasy

A: quirk
****
Q: Category: SPLIT OWNERSHIP 
Clue: Lake Titicaca

A:
peru & bolivia
****