阅读下列材料，从每题所给的四个选项（A、B、C和D）中，选出最佳选项。
A
How often do you travel by plane?
How much electricity do you use? These days everyone is worried about the size of their carbon footprint. In order to reduce global warming we need to make our carbon footp rints smaller. But how much CO2 are we responsible for?
A new book by Mike Berners Lee (a leading expert in carbon footprint) might be able to help. How Bad are Bananas? The Carbon Footprint of Everything looks at the different things we do and buy, and calculates the
