During the industrialization, England's population almost tripled. It means that the birth rate was high and the death rate must have been low. Pre-modern era, though, was a very dark place with low life expectancy and woman had to provide children almost as an obligation. Also, we weren't provided with the technology or cultural knowledge that allows us to live longer and avoid diseases.
The answer would be along the lines of problems with federal authority linked with the articles of confederation but in this case I would go with "D) The United States was a weak nation."