D. A plateau period means that there is no change, bad or good. Options A-C are exciting changes, meaning there is an uphill change. However in D, nothing is changing at all.
The Sahara, the largest hot desert in the world, covers 3.3 million square miles and is located in the northern part of Africa. The Kalahari Desert, located in southern Africa, covers 362,500 square miles. The Namib Desert, the world's oldest desert, is found in the southwestern portion of the continent and covers 100,000 square miles.
During the era of slavery in the United States, the education of African Americans, enslaved and free, was often discouraged, except for religious instruction, and eventually made illegal in many of the Southern states. It was believed that literacy was a threat to the institution of slavery. First, literacy facilitated knowledge about the successful slave revolution in Haiti of 1791–1804, the end of slavery in the British Empire in 1833, and the writings of abolitionists. Secondly, literacy allowed or potentially allowed slaves better access to information about the Underground Railroad and other routes to freedom.
