Final answer:
The central idea of 'Paper or Plastic, neither!' is the environmental impact of both paper and plastic bags.
Step-by-step explanation:
The central idea of the given text, 'Paper or Plastic, neither!' is c) The environmental impact of both paper and plastic bags.
The passage discusses the problems associated with plastic use, including its contribution to air and water pollution, as well as its hazards to animals and marine life.
Additionally, the passage mentions that plastic waste fills landfills, highlighting the environmental impact of plastic bags.