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: I'M JUST RUNNING IN FOR... 
Clue: ...20 first-class stamps, which will now cost this much total
$7.40

Category: ENTERTAINERS 
Clue: Lauren Bacall coined this name for a carousing group including Humphrey Bogart, Judy Garland & Frank Sinatra
\"the rat pack\"

Category: CLEANING UP 
Clue: In 1887 Johnson & Johnson was incorporated in part to improve upon this man's study of antisepsis

lister