Read the following article and answer the question. Article: Chicken feathers are useful, and not just to a chicken. Some go into pillows, coats and other products. But countless chicken feathers go to waste. In the United States, billions of chickens are produced yearly. Most of their feathers are thrown away. But instead of being buried in land, some feathers could find a future in plastics . One of the products they have developed is a flowerpot . It may look like other flowerpots. But the container breaks down in the earth within one to five years. And as it _ , it naturally becomes nutrient in the soil. The environmentally friendly flowerpot is the work of two researchers. Walter Schmidt is with the Agricultural Research Service, part of the United States Agriculture Department. Masud Huda is with the Horticultural Research Institute, a private organization . Walter Schmidt has been working to find uses for chicken feathers since the 1990s. Progress in 2002 showed that plastic made from feathers could be formed like other plastics. He says feathers are much stronger and last longer than another plant material. "Feathers are stronger. By design, feathers are also more durable . And the other part about it is if feathers were twice as heavy, or half as strong, then birds couldn't fly." He points out that traditional flowerpots made from other plastics can last much longer. But he wonders if there is really a need. He says most flowerpots are never re-used. "Why would you want a plastic that you use for a year to last for two hundred years? It makes no sense. You want to match the product with the use." said Walter Schmidt. Walter Schmidt and Masud Huda are now adding another chicken product to their flowerpots -- chicken waste. The waste will add more nutrients to the soil as the pot breaks down. The scientists say they hope their flowerpot will be on the market in a year or two. Question: What do you think is the main idea of the passage? Answer:

Available options: i. Chicken and its feathers. ii. How to deal with feathers. iii. feathers made into flowerpot. iv. New flowerpots.
The answer is:
iii.