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: THE 10 LARGEST COUNTRIES IN THE WORLD 
Clue: The one that spans 11 time zones
[A]: russia


[Q]: Category: THE 1970s 
Clue: In 1977 Bank of America changed the name of its Bank Americard to this 4-letter word
[A]: visa


[Q]: Category: TO THE NEAREST... 
Clue: To the nearest billion, number of Cokes you'd need to buy to give one to everyone in the world
[A]:
6 billion