TASK DEFINITION: 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.
PROBLEM: Category: A CHRISTMAS POTPOURRI 
Clue: On Christmas Eve 1968, Borman, Lovell & Anders became the first men to circle this object

SOLUTION: the moon

PROBLEM: Category: ISLANDS 
Clue: Delos, the smallest of this country's Cyclades Islands, was a shrine to Apollo in ancient times

SOLUTION: greece

PROBLEM: Category: HOLIDAYS & OBSERVANCES 
Clue: It's celebrated the evening before All Saints' Day

SOLUTION:
all hallow\'s eve