Answer:
Option: A. Stimulated the coal mining industry.
Step-by-step explanation:
The industrialization in America began in 1800. With the availability of coal and other natural resources helped the industries to flourish. The railroad industry at the beginning of the 19th century supports coal mining industry to grow rapidly. Coal became necessary fuel for railways to operate their engines as it became a cheap and efficient source of power for steam engines. As the coal mining expanded in 1900, some coal mine use new methods compared to the old technique of using picks and shovel to extract the coal.