- Wed Mar 05, 2025 2:43 pm
#112181
Hi Saiffshaikhh!
Let's break down our stimulus:
Premise 1: Concerns for the environment have led chemists to develop degradable plastics.
Premise 2: All degradable plastics, which are potentially useful for packaging, need just the right conditions to break down.
Premise 3: Some need sunlight, some need to be buried in soil, some need to be submerged in water.
Premise 4: Some degradable plastics leave residues of unknown toxicity.
Based on these premises, which of the following answer choices must be true?
Answer Choice D states: "Some materials that leave residues of unknown toxicity are not degradable plastics."
This Answer Choice is out of scope. Our stimulus is solely dealing with the concept of degradable plastics, and the fact that they may leave residues of unknown toxicity. Sure, any number of other materials may leave residues of unknown toxicity. However, that doesn't matter to us in the context of this question.
Answer Choice A states: "Some materials that are potentially useful for packaging leave residues of unknown toxicity."
We know that all degradable plastics are potentially useful for packaging, and that some degradable plastics leave residues of unknown toxicity. Therefore, it must follow that at least some materials useful for packaging leave residues of unknown toxicity.
I hope this helps!
