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.

[Q]: Category: YOU NEED THERAPY 
Clue: In the hyperbaric type of this "therapy", the patient inhales the pure gas in a large chamber
[A]: oxygen


[Q]: Category: ARTS & CRAFTS 
Clue: This form of needlework uses a hooked needle to pull the yarn through intertwined loops
[A]: crochet


[Q]: Category: WE ALL WANT TO CHANGE THE WORLD 
Clue: In 1996 this president of South Africa oversaw the enactment of a new democratic constitution
[A]:
nelson mandela