A.I. Explanation:

Option 1: "Being the fastest runner in his team."

Explanation: This option is incorrect because the text does not mention Jackie Robinson's speed or running ability as a defining achievement. Instead, it focuses on his role as a trailblazer and his contributions to the team, particularly in leading them to success.

Option 2: "Winning the World Series single-handedly."

Explanation: This option is incorrect because the text states that Robinson's team won the World Series in 1955, but it does not attribute this victory solely to him. The phrase 'single-handedly' implies that he was solely responsible, which contradicts the collaborative nature of team sports.

Option 3: "Becoming the first black player in Major League Baseball."

Explanation: This option is correct as the text explicitly states that Jackie Robinson was signed by Branch Rickey when there were no black players in Major League Baseball, highlighting his significance as a trailblazer. This achievement is central to Robinson's legacy in the sport.

Option 4: "Inventing a new style of baseball play."

Explanation: This option is incorrect because the text does not mention any innovation in playing style attributed to Jackie Robinson. Instead, it emphasizes his role as a pioneer and his achievements in leading his team to success.