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: RIVERS
Clue: The mouth of this 2315-mile-long river lies in the Mississippi River 17 miles above St. Louis
the missouri

Category: THE MISSPELED WORD
Clue: An absence of leisure may leave you feeling like you live in the Artic
artic/arctic

Category: SCIENTISTS
Clue: Using a prism, this Englishman proved that white light is a combination of the colors of the spectrum
sir isaac newton