Select the letter of the topic that could best be organized using a timeline. a. a cross-country train ride c. an obstacle course b. rainbow d. a famous painting

The correct answer is A. A cross-country train ride could best be organized using a timeline, since a timeline could be used to organize arrivals and departures of trains to each one of the different stations of the route, for example.  This would provide users with detailed information about the service, and allow a better organization of the trips.