单选题：Questionsare based on the following passage.International g

Questionsare based on the following passage.
International governments' inaction concerning sustainable development is clearly worrying but the proactive (主动出击的) approaches of some leading-edge companies are encouraging. Toyota, Wal-Mart, DuPont, M&S and General Electric have made tackling environmental wastes a key economic driver.
DuPont committed itself to a 65% reduction in greenhouse gas emissions in the 10 years prior to 2010.By 2007, DuPont was saving $2.2 billion a year through energy efficiency, the same as its total declared profits that year. General Electric aims to reduce the energy intensity of its operations by 50% by 2015.They have invested heavily in projects designed to change the way of using and conserving energy.
Companies like Toyota and Wal-Mart are not committing to environmental goals out of the goodness of their hearts. The reason for their actions is a simple yet powerful realisation that the environmental and economic footprints fit well together. When M&S launched its "Plan A" sustainability program me in 2007,it was believed that it would cost over ~200 million in the first five years. However, the initiative had generated ~105 million by 2011/12.
When we prevent physical waste, increase energy efficiency or improve resource productivity, we save money, improve profitability and enhance competitiveness. In fact, there are often huge "quick win" opportunities, thanks to years of neglect.
However, there is a considerable gap between leading-edge companies and the rest of the pack. There are far too many companies still delaying creating a lean and green business system, arguing that it will cost money or require sizable capital investments. They remain stuck in the "environment is cost "mentality. Being environmentally friendly does not have to cost money. In fact, going beyond compliance saves cost at the same time that it generates cash, provided that management adopts the new lean and green model.
Lean means doing more with less. Nonetheless, in most companies, economic and environmental continuous improvement is viewed as being in conflict with each other. This is one of the biggest opportunities missed across most industries. The size of the opportunity is enormous, The 3% Report recently published by World Wildlife Fund and CDP shows that the economic prize for curbing carbonemissions in the US economy is $780 billion between now and 2020. It suggests that one of the biggest levers for delivering this opportunity is "increased efficiency through management and behaviouralchange"--in other words, lean and green management.
Some 50 studies show that companies that commit to such aspirational goals as zero waste, zeroharmful emissions, and zero use of non-renewable resources are financially outperforming their competitors. Conversely, it was found that climate disruption is already costing $1.2 trillion annually, cutting global GDP by 1.6%. Unaddressed, this will double by 2030.
What does the author say about some leading-edge companies? A．They operate in accordance with government policies.
B．They take initiatives in handling environmental wastes.
C．They are key drivers in their nations' economic growth.
D．They are major contributors to environmental problems.