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: HISTORIC LASTS 
Clue: In the "thanks a lot, fellas" department, Mongolia was the last country to join this group--August 9, 1945
the allies

Category: WORLD HISTORY 
Clue: City that was the seat of government of the viceroyalty of New Spain
mexico city

Category: MOVIES 
Clue: A catering hall called Aphrodite's Palace is featured in this 2002 film

my big fat greek wedding