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.

Category: A CAST OF THOUSANDS 
Clue: It's what you're trying to catch when you're fly-casting
fish

Category: BRAZIL 
Clue: It got its name after a Spanish explorer reported being attacked by female warriors there
amazon river

Category: EDUCATION 
Clue: Back in 1987 Aspen College began offering an MBA degree online, MBA standing for this

master\'s of business administration