From the information in Passage 1, the best conclusion about residents of Portland, Oregon, is:
D. They have greatly reduced their landfill trash.
The sentence that supports this conclusion is:
C. “Instead of sending these items to the landfill, people can set aside leftovers and use them for animal feed or compost them for fertilizer.” (paragraph 4)
This indicates that residents are finding alternatives to sending waste to landfills, which implies a reduction in landfill trash.