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: SCIENCE 
Clue: This yellow element is found in gunpowder & matches & is used in vulcanizing rubber

SOLUTION: sulphur

PROBLEM: Category: THE COMPUTER AGE 
Clue: Dan Bricklin developed VISICALC, the first of these programs, similar to an accounting ledger

SOLUTION: spreadsheet

PROBLEM: Category: STRANGE HISTORY 
Clue: This "rock" of a general was an unpopular teacher at VMI before the Civil War & was often the target of pranks

SOLUTION:
stonewall jackson