Step-by-step explanation:
B. Divided the United States into time zones.
In 1883, the railroads in the United States divided the country into four time zones to make their schedules more standard. Prior to this, each town or city had its own local time based on the position of the sun, which made it difficult for trains to keep to a schedule. With the adoption of standardized time zones, train schedules could be created and followed more easily, which allowed for more efficient and reliable transportation.