By the end of the Civil War, C. the South's economy had been destroyed.
North had won and destroyed everything good in South as a result of this War. South had to rebuild its economy after the war, which took a long time to do.
The correct answer is: an extreme political ideology.
Indeed, the movement’s ideology was a very dogmatic blend of several ideologies and outlooks. They were heavily Stalinist and Maoist in their leftism; extremely xenophobic against both foreigners and national non-Khmer minorities and extremely agrarian.
With regards to their Stalinist/Maoist outlook they believed in absolute obedience to the party and its leaders, with a set of inviolable strict rules and laws and the belief that the ends justified any means.
They loathed national minorities as they saw them as a stain on their national Khmer purity and they despised foreigners because they refused to ever be colonized again, whether by Westerners or Asians.
They also considered that urban, capitalistic society was a disease and sought to eradicate it by eradicating its people.
That would be D. Woodrow Wilson
The correct answer is spain