Final answer:
In the World Series, a team must win four games to clinch the championship, following a best-of-seven format.
Step-by-step explanation:
The World Series in baseball is a championship series played between the winners of the American League and the National League. The series follows a best-of-seven format, which means that the first team to achieve four victories wins the championship. Therefore, the correct answer to the question is three: Four games are needed to win the World Series.