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: MEAN GIRLS 
Clue: This supernatural TV series was full of mean girls: Cordelia, the insane vampire Drusilla & Glory (a sort of evil god)

SOLUTION: buffy the vampire slayer

PROBLEM: Category: MEDICINE 
Clue: Robert Koch, in 1876, was the first to identify the bacterium causing a specific disease, this disease of cattle & man

SOLUTION: anthrax

PROBLEM: Category: "E" BAY 
Clue: Thinking green, biologist Ernst Haeckel coined this term for the way animals interact with the environment

SOLUTION:
ecology