The correct answer is B. off.
People in large cities are cut off from nature because they are surrounded by buildings and other man-made structures. This can make it difficult to find places to connect with nature, such as parks or green spaces. Additionally, the noise and pollution in cities can make it difficult to appreciate the natural world.
Option A, away, is incorrect because it suggests that people in large cities are physically removed from nature. This is not always the case, as many cities are located near natural areas. However, the built environment can make it difficult for people to access these areas.
Option C, out, is incorrect because it suggests that people in large cities are not interested in nature. This is not necessarily the case, as many people in cities enjoy spending time outdoors. However, the built environment can make it difficult for people to find opportunities to connect with nature.
Option D, down, is incorrect because it suggests that people in large cities are inferior to those who live in rural areas. This is not a valid assumption, as there are many benefits to living in both urban and rural areas.