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: EXPLORERS 
Clue: On hearing of the discovery of George Mallory's body, this man told reporters he still thinks he was first
sir edmund hillary

Category: THE 20th CENTURY 
Clue: In the 1940s Franklin Roosevelt coined this term in reference to all the countries allied against the Axis powers
united nations

Category: WORLD EVENTS 
Clue: In 2003, 120 years after it made headlines, a book on this was subtitled "The Day the World Exploded"

the eruption of krakatoa