Final answer:
The sentence that best fulfills the teacher's purpose of determining the meanings of words according to their contexts is option C. Correct option is C.
Step-by-step explanation:
The sentence that best fulfills the teacher's purpose of determining the meanings of words according to their contexts is option C. "Omnivorous" animals prefer eating both plants and meat. This sentence provides the context for the word "omnivorous" by explaining that it refers to animals that eat both plants and meat. By understanding the context of the word, students can infer its meaning.