You are presented with the question "Global warming most threatens the Earth's ability to do what?" and the following answer choices: 
- Sustain life
 - reproduce
 - Melt polar ice caps
 - growth
 - protect them
 - Resist erosion
 - to move people
 - Produce fossil fuels

Now knowing that if a planet becomes too hot then that planet cannot sustain life and global warming linked to human emissions of heat-trapping gases is changing the planet's climate, choose the best answer.


 

 Sustain life        