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.

Q: Category: COUNTRIES OF THE WORLD 
Clue: The 3 most populous countries, they added up to an estimated 2.42 billion people in 1996

A: china, india, & the usa
****
Q: Category: NORTH AMERICAN BIRDS 
Clue: This bird is known for its size (5 feet tall), its call (carries 2 miles) & its rarity; in 1941 there were only 21 in the wild

A: the whooping crane
****
Q: Category: AMERICANA 
Clue: Finding the spot for this memorial caused its creator to say, "America will march along that skyline"

A:
mount rushmore
****