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 simplicity, answers should be in all lower cased letters.
PROBLEM: Category: ON THE COAST 
Clue: A 19th c. "Committee of Vigilance" fought the crime that gave part of San Francisco this North Africa-inspired nickname

SOLUTION: the barbary coast

PROBLEM: Category: HALOGENS 
Clue: A reddish liquid, this halogen is often used to make sedatives & was once used to make EDB, an additive in lead gasoline

SOLUTION: bromine

PROBLEM: Category: LEAF ME 
Clue: The Macrocystis genus of this seaweed can grow fronds up to 200 feet long

SOLUTION:
kelp