The author uses a cause-and-effect relationship to show that human invasion of bear territory has resulted in the increased encounters. The correct answer is option D.
The first paragraph develops the idea that humans are responsible for the rise in bear encounters by using a cause-and-effect relationship. The author shows that the increased encounters between humans and bears are a result of human invasion of bear territory. By entering and disrupting the natural habitat of bears, humans have unintentionally caused more frequent interactions between the two species. This cause-and-effect relationship helps to establish the connection between human activities and the rise in bear encounters.
The first paragraph does not use a problem-and-solution relationship to show how humans have prevented encounters with bears in the past. It also does not focus on comparing and contrasting the behavior of bears today with their past behavior. While the first paragraph may touch on the chronological order of events that have led to the increase in encounters between humans and bears, it primarily emphasizes the cause-and-effect relationship between human invasion of bear territory and the increased encounters.
Therefore, the correct answer is D. The author uses a cause-and-effect relationship to show that human invasion of bear territory has resulted in the increased encounters.