<span>B.) Martin Luther's writing of his "95 Theses" inspired the invention of printing.</span>
Cotton Gin was a technological development that led to an increased demand for slaves in the United States during the early - mid 1800's. The cotton gin made it easier to separate seeds from the cotton - making it faster to pick cotton!
I believe it is because they were still reeling from World War I and hoped to avoid another large-scale conflict.