Question #N517

The following text is adapted from a 19th-century travelogue by explorer Richard Francis Burton. Burton writes about his travels across Africa, describing the inhabitants and landscapes that he encounters. "A great deal of the country is mere swamp, or what is known as the *sudd*. This is a mass of vegetation, chiefly papyrus reeds, growing so thickly that it is almost impossible to penetrate it. The *sudd* is so dense and widespread that it forms a network of channels through which navigation is slow and dangerous. I am told that it is difficult to clear it, as the dense reeds are of a very tenacious quality."

Which choice best describes the structure of the passage?
A. The passage begins by introducing a general topic, describes a particular feature of the environment, and then explains the challenges that feature presents.
B. The passage presents a series of factual observations about a particular location and then provides a general conclusion based on those observations.
C. The passage contrasts the landscape of one region with the landscape of another region, and then explains the reason for the difference between the regions.
D. The passage describes a significant event in the author’s travels and then explains the challenges that the author faced during the event.