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: 20th CENTURY AUTHORS 
Clue: His "Fictional Memoir" about his last African safari was published in 1999, 38 years after his death

SOLUTION: ernest hemingway

PROBLEM: Category: ACTORS 
Clue: In 1970 he became the first professional actor to be named a lord

SOLUTION: laurence olivier

PROBLEM: Category: MACHINES 
Clue: This brand name comes from machines devised by Benjamin Holt to crawl over soft farmland

SOLUTION:
caterpillar