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: WORLD CAPITALS 
Clue: This capital city of 113,000 is the closest national capital to the Arctic Circle
reykjavík

Category: SUBWAY STOPS 
Clue: You can ride one line in this world capital from Kifissia to Pireas
athens

Category: GROUPS 
Clue: Murderous right-wing groups that roamed El Salvador in the 1980s were called "death" these

squads