The World Series of baseball was a best-of-nine-games contest in 1903 (the first year of the World Series) 1920 and 1921.
a. No change
b. The World Series of baseball was a best-of-nine-games contest in 1903 (the first year of the World Series) 1920, and 1921.
c. The World Series of baseball was a best-of-nine games contest in 1903 (the first year of the World Series), 1920, and 1921.