As a form of public transportation, trains are faster than buses and more accessible than subways. Furthermore, in most situations, constructing a train line is much less expensive than establishing a subway line. In most situations, as a result, establishing a railroad is the best way to connect communities, except for communities that derive most of their income from winter sports tourism.
Which of the following, if true, would best explain the exception given above?
【选项】
Building a railway is much more expensive than other forms of transport in mountainous terrain.
选项是否正确？