Many environmentalists and entrepreneurs are looking for ideas on how to "capture gold" -- that is, how to collect and convert plastic waste into new plastic or fuel. OK, describing plastic waste as potential "gold" may be overdoing it.  But the campaigners say that publicizing the notion that plastic is worth something may help reduce the amount of waste that ends up in oceans and the bellies of sea creatures. To that end, they have set up a competition inviting members of the public to submit ideas online.  Organizers will take the best ones to the Rio+20 Earth Summit   in Rio de Janeiro next month, where they are planning a daylong side event called Plasticity focusing on issues related to plastic pollution. The plastic waste problem is gaining broader attention as environmentalists, scientists, manufacturers and the public become more aware of the sheer volume of the stuff that finds its way into the sea. More than 260 million metric tons of plastic are now produced per year, according to the trade association PlasticsEurope.  The majority of that is not recycled.  Most of it ends up in landfill, and a significant amount ends up as litter on land, in rivers and in the oceans. Technological advances have made clear that it is possible to reuse much of this plastic by turning it into fuel or new products.  Yet the companies that have come up with such solutions have not achieved the economies of scale that would allow them to function profitably.  Insufficient waste-collection and recycling systems in most countries also stand in the way of " _ " concept, said Doug Woodring, an environmental entrepreneur in Hong Kong who is among the organizer of the Plasticity forum  in Rio. Rather than breast-beating, the form aims to highlight some of the technologies and ideas out there for collection and reuse.  My personal favorite for now is a vacuum cleaner with plastic parts made from plastic waste. What do the campaigners like to do exactly?
To describe plastic waste as potential "gold". To invite members of the public to their forum. To collect ideas on how to recycle plastic waste. To hold a competition on how to deal with environmental pollution.
Question: Many environmentalists and entrepreneurs are looking for ideas on how to "capture gold" -- that is, how to collect and convert plastic waste into new plastic or fuel. OK, describing plastic waste as potential "gold" may be overdoing it.  But the campaigners say that publicizing the notion that plastic is worth something may help reduce the amount of waste that ends up in oceans and the bellies of sea creatures. To that end, they have set up a competition inviting members of the public to submit ideas online.  Organizers will take the best ones to the Rio+20 Earth Summit   in Rio de Janeiro next month, where they are planning a daylong side event called Plasticity focusing on issues related to plastic pollution. The plastic waste problem is gaining broader attention as environmentalists, scientists, manufacturers and the public become more aware of the sheer volume of the stuff that finds its way into the sea. More than 260 million metric tons of plastic are now produced per year, according to the trade association PlasticsEurope.  The majority of that is not recycled.  Most of it ends up in landfill, and a significant amount ends up as litter on land, in rivers and in the oceans. Technological advances have made clear that it is possible to reuse much of this plastic by turning it into fuel or new products.  Yet the companies that have come up with such solutions have not achieved the economies of scale that would allow them to function profitably.  Insufficient waste-collection and recycling systems in most countries also stand in the way of " _ " concept, said Doug Woodring, an environmental entrepreneur in Hong Kong who is among the organizer of the Plasticity forum  in Rio. Rather than breast-beating, the form aims to highlight some of the technologies and ideas out there for collection and reuse.  My personal favorite for now is a vacuum cleaner with plastic parts made from plastic waste. What do the campaigners like to do exactly?
A. To describe plastic waste as potential "gold".
B. To invite members of the public to their forum.
C. To collect ideas on how to recycle plastic waste.
D. To hold a competition on how to deal with environmental pollution.
Answer: