单选题 .  Amtrak (美国铁路客运公司) was experiencing a downswing in ridership (客运量) along the lines comprising its rail system. Of major concern to Amtrak and its advertising agency DDB Needham, were the long-distance western routes where ridership had been declining significantly. At one time, trains were the only practical way to cross the vast areas of the west. Trains were fast, very luxurious, and quite convenient compared to other forms of transportation existing at the time. However, times change and the automobile became America's standard of convenience. Also, air travel had easily established itself as the fastest method of traveling great distances. Therefore, the task for DDB Needham was to encourage consumers to consider other aspects of train travel in order to change their attitudes and increase the likelihood that trains would be considered for travel in the west.
    Two portions of the total market were targeted: 1) anxious fliers—those concerned with safety, relaxation, and cleanliness and 2) travel-lovers—those viewing themselves as relaxed, casual, and interested in the travel experience as part of their vacation. The agency then developed a campaign that focused on travel experiences such as freedom, escape, relaxation, and enjoyment of the great western outdoors. It stressed experiences gained by using the trains and portrayed western train trips as wonderful adventures.
    Advertisements showed pictures of the beautiful scenery that could be enjoyed along some of the more famous western routes and emphasized the romantic names of some of these trains (Empire Builder, etc.). These ads were strategically placed among family-oriented TV shows and programs involving nature and America in order to most effectively reach target audiences. Results were impressive. The Empire Builder, which was focused on in one ad, enjoyed a 15 percent increase in profits on its Chicago to Seattle route.1.  What's the author's purpose in writing this passage? ______