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: SPORTS CHAMPIONS 
Clue: Winning in 1965 & 1966, he was the first man to win the Masters golf tournament in 2 consecutive years
jack nicklaus

Category: ALL GOD'S CREATURES 
Clue: Edison proposed a flying machine based on the flight of this creature, also the subject of a musical work
bumblebee

Category: RIVERS 
Clue: The name of this river whose lower reaches run through Ghana is from Portuguese for "turn" or "bend"

the volta