What is one reason why the expansion of the railroads caused prices of products to drop during the gilded age?
railroads provided transportation for products to markets in rural areas of the south.
railroads provided cheap and fast transportation for both raw materials and products.
railroads provided fast transportation of raw materials to ports for overseas shipments.
railroads provided expensive but fast transportation of raw materials and products.

The answer is given by the second sentence which explains that “Railroads provided cheap and fast transportation for both raw materials and products.”. Aside from this, another reason was because agricultural products were being overproduced by that time. There were too many products available in the market which is why the prices became too low. 

because mexico wanted to choose a centralized location

b - those executed came from every social and economic class