The correct answer is C. The development of machines, including steam engines, and England's many natural reserves of coal.
Explanation
The map shows a map of England specifying the following characteristics: Towns with over 20,000 people (black circles), exposed coalfields (green shapes), industrial areas (red borders), the center of woolen cloth production, 18th century (purple shapes), and principal railroads (black lines)
According to the above, the map shows the railway connection that existed between the large industrial centers in which steam engines were used and the coal deposits. This allows us to visualize that England had a wide development of industrial zones that were perfectly connected between them and the seaports to get their products to other countries. Additionally, coal deposits were connected to large industrial centers because they represented one of the materials necessary for the operation of steam engines in factories. Therefore, the correct answer is C. The development of machines, including steam engines, and England's many natural reserves of coal.