Answer:
Railroads provided cheap and fast transportation for both raw materials and products.
Step-by-step explanation:
When the cost of production drops, the sellers and merchants are able to offer a better-lower cosot for their buyers, when the railroads started expading, the new-cheaper way of transportation made it possible for products and raw materials to lower their production cost, this meant that they were able to offer the same products and materials at a cheaper cost.