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: AMERICAN PLAYWRIGHTS 
Clue: Around 1912, while recovering in a sanatorium, this former seaman decided to become a playwright
eugene o\' neill

Category: SIGNS & SYMBOLS 
Clue: Created in 1970 & made up of 3 arrows, the universal symbol for this was based on the Mobius strip
recycling

Category: POP CULTURE 
Clue: Also the title of one of the best-selling albums of all time, it was first seen in Russian photos taken in 1959

the dark side of the moon