Through Topeka airport, the volume of plane travel is just enough for the commercial airlines to make modest profits. The size of the city's population is stable and is not expected to increase much. Yet there are investors ready to double the number of flights to and from the airport within ten years, and they are predicting solid profits both for themselves and for the established airlines.
Which of the following about the city of Topeka, if true, most helps to provide a justification for the investors' prediction?
【选项】
Spending on train and bus travel to and from Topeka has been increasing modestly each year for the past ten years.
选项是否正确？