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.

[EX Q]: Category: WORLD RIVERS 
Clue: With 4, more national capitals are located on this river than any other river in the world
[EX A]: the danube

[EX Q]: Category: THE MIDWEST 
Clue: To journey through 3 adjacent states that start with the same letter, you have to go through these 3
[EX A]: iowa, illinois & indiana

[EX Q]: Category: EUROPEAN RIVERS 
Clue: 20 miles from Frankfurt is the meeting place of these 2 rivers, whose names rhyme despite the spelling
[EX A]:
the rhine & the main