Refer to the NASA article "Responding to Climate Change." How does this sentence develop the concept that people must try to limit climate change immediately?

The goal is to reduce our vulnerability to the harmful effects of climate change.

A. It shows that the earth and future generations will be affected by climate change.

B. It shows that people are becoming more aware of the problems that arise from climate change.

C. It describes climate change as a destructive condition to which people are susceptible.

D. It suggests the steps people can take to reduce changes in the earth's climate.