Arguably the main difficulty in maintaining the large land empire of Russia was a "<span>C. lack of industrialization," since this made it nearly impossible for Russia to "catch up" with the West. </span>
We can say that the consequence of the Age of Enlighenment were the French Revolution and the American Revolution , because people were moved by the idea of a society as a social contract between government and governed. Ideas that were developed by Montesquie in the Age of Enlightenment.
The correct answer should be C. Give their lands to settlers. More and more settlers started arriving and the late 1700s were the period when the first policies for removing the natives from their land started taking place. This would go on into the 1800s and result in all the wars and bloodshed that ensued in the period.