Answer:
Answer: D) Express a viewpoint.
Explanation: in the given paragraph we can see that the speaker is describing how the students discard large amounts of uneaten food during lunch, which ends up in a landfill, producing pollution and gases that harm the environment. In the first sentence, the writer says that he has noticed this problem, which implies that he uses this sentence to clarify that he is expressing his point of view.
Step-by-step explanation: