The correct answer is B) to make train schedules simpler.
In 1883, the reason that led Congress to establish time zones in America was to make train schedules simpler.
On November 18, 1883, Railroads in the United States started to use standard times with four different time zones: Pacific, Mountain, Central, and Eastern. So every part of the country synchronized their clocks with this new system and train schedules became simpler.
However, time-zone became official in the United States until 1918, with the passage of the Standard Time Act.