Which statement summarizes the lesson the best?

Варианты ответов и условие задания

1. While the total amount of water on the Earth never changes, we still need to take actions to avoid regional scarcity.
2. The total amount of water on the Earth never changes, so we don’t need to worry about conserving it.
3. Water scarcity is real, and there is absolutely nothing we can do about it.
4. Water scarcity is real, but an individual has little power to make a change.