Answer:
Option D.
Step-by-step explanation:
Conflicting train schedules, is the right answer.
A time zone is a zone of the earth that follows a uniform standard time for economic, social and legal purposes. Time zones manage to reflect the borders of nations and their neighborhoods instead of longitude because it is suitable for regions in close economic or other information to keep the identical time. However, the time zones were adopted to fix conflicting train schedules.