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.

[EX Q]: Category: GEOLOGISTS 
Clue: In 1957 Sir Vivian Fuchs led the first crossing of this continent; it took 99 days
[EX A]: antarctica

[EX Q]: Category: "F" IN ANATOMY 
Clue: Hairs grow out of these pouchlike openings
[EX A]: follicles

[EX Q]: Category: THE ELEMENTS 
Clue: 2 of the ores for this yellowish-green gas are rock salt & horn silver
[EX A]:
chlorine