What is the purpose of the author in writing the passage？A．To call on people to reduce car

What is the purpose of the author in writing the passage？

A．To call on people to reduce carbon footprints.

B．To offer tips on how to live a low-carbon life.

C．To introduce the research on carbon footprints.

D．To clear up misunderstandings about carbon emission.

请帮忙给出正确答案和分析，谢谢！