Answer:
A. Markets went from global to national as goods could be sold across the country.
Step-by-step explanation:
The availability of natural resources like timber, coal, iron, etc. favoured establishment of industries. Railways enabled faster transportation of these materials throughout the united states.
Similarly, the goods produced from these materials were transported quickly and sold throughout the country.
Railways provided a major boost to industrialization, mainly coal and steel industries.
Railways had thus become crucial to the existence of industrial economy in united states.