Humans have discarded as much as 1 billion tons of plastic since the 1950s, and this waste may have existed for hundreds or even thousands of years. Recently, a research team found a fungus called endophyte in the Amazon rainforest. It cancan degrade ordinary polyurethane plastics. Researchers believe that using the characteristics of this fungus will help humans eliminate the threat posed by plastic waste. Which of the following prerequisites should the researchers use to make their judgments? ['Plastic waste is the most important type of waste generated by human activities.', 'Endophytes can decompose plastic products well under any conditions.', 'At present, most plastic waste belongs to ordinary polyurethane plastic.', 'This fungus can survive and grow normally in other parts of the planet.']