Enclosure is also considered one of the causes of the Agricultural Revolution. Enclosed land was under control of the farmer, who was free to adopt better farming practices. Following enclosure, crop yields and livestock output increased while at the same time productivity increased enough to create a surplus of labor.
The Lincoln–Douglas debates (also known as The Great Debates of 1858) were a series of seven debates between Abraham Lincoln, the Republican candidate for the United States Senate from Illinois, and incumbent Senator Stephen Douglas, the Democratic Party candidate.
The answer to your question is D.
