Which statement best expresses the main idea in the article?

A. climate change is unstoppable, and people worldwide need to prepare for how this will change their lives.
B. If at least half the world starts living green and making changes, climate change will definitely slow down.
C. If people work together to solve problems; there could be many ways to slow down climate change.
D. It will take future young leaders, like the high schoolers in this text, to end.