The correct answer to this question would be alternative 2/B)"Transportation improving with stage and Pony Express connections."
In the early stages of the American West, the West was sort of a wild land, and means of transportation at the time were really precarious, using mostly horses and wagons, which made trade with distant territories challenging.
With the implementation of railroads connecting the West to the East, it was possible for Westerners to profit from trade, since transportation became more efficient and reliable.