TASK DEFINITION: Given an trivia question precisely answer the question with a word/phrase/name. External resources such as Wikipedia could be used to obtain the facts.
PROBLEM: Three of the Galilean moons of Jupiter are Io, Europa and Callisto. Which is the fourth?

SOLUTION: ganymede

PROBLEM: For which club was Zinedine Zidane signed when voted World Footballer Of The Year in 1998 and 2000?

SOLUTION: juventus f.c.

PROBLEM: Who composed `The Four Seasons`?

SOLUTION:
vivaldi