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 consistency, answers should be in all lower cased letters.

Category: ANCIENT TIMES 
Clue: Julius Caesar said this region was divided into 3 parts; Augustus divided it into 4, including Aquitania
gaul

Category: "Y"? 
Clue: You can split the atom or even do barrel rolls using this toy
a yo-yo

Category: HARK, IT'S ARKANSAS! 
Clue: A member of this illustrious & wealthy family was governor of Arkansas from 1967 to 1971

rockefeller