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 consistency, answers should be in all lower cased letters.
PROBLEM: Category: "TA" TA FOR NOW 
Clue: In English the name of the main text of this religion means "The Classic of the Way and its Power"

SOLUTION: taoism

PROBLEM: Category: ENVIRONMENTALISM 
Clue: The world's first national park was Yellowstone, opened in 1872; this country opened its first park at Banff in 1887

SOLUTION: canada

PROBLEM: Category: MY FAVORITE FILMS 
Clue: At one point, John Huston wanted Gable & Bogart to star in this film about 2 schemers who want to rule Kafiristan

SOLUTION:
the man who would be king