What is the text structure of the following paragraph?
The chief and immediate cause of the Civil War was slavery. Southern states, including the 11 states that formed the Confederacy, depended on slavery to support their economy. Southerners used slave labor to produce crops, especially cotton. Although slavery was illegal in the Northern states, only a small proportion of Northerners actively opposed it. The main debate between the North and the South on the eve of the war was whether slavery should be permitted in the Western territories recently acquired during the Mexican War (1846-1848), including New Mexico, part of California, and Utah. Opponents of slavery were concerned about its expansion, in part because they did not want to compete against slave labor.
a.
narrative
b.
expository
c.
descriptive
d.
persuasive