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: RIVERS 
Clue: In 1951 it was determined that this river's source was in the Sierra Parima of Venezuela
[A]: the orinoco


[Q]: Category: ENDS IN "I" 
Clue: Stephen S. Wise was a well-known one; Isaac Bashevis Singer was the son of one
[A]: a rabbi


[Q]: Category: BROTHERS IN BUSINESS 
Clue: Last name of Walter & Arthur, who partnered up with William Harley in 1903
[A]:
davidson