Why did the development of time zones make train schedules more reliable? a)time zones set the entire country to the same time. b)time zones measured time locally instead of country-wide. c)time zones made sure that each state was in only one zone. d)time zones created a standard of time that all trains followed.

The answer is: D)Time zones created a standard of time that all trains followed.

Due to the development of railroad technology, trains could cover the distance between areas that have different time zones. Since a lot of the customers use it to commute for works, it is very important for standardized time to be created for all trains

option c

explanation:

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