I think it’s D!
In a sentence using passive voice, the subject is acted upon; he or she receives the action expressed by the verb. The agent performing the action may appear in a "by the..." phrase or may be omitted. The dog is acting upon the sentence subject (the boy), meaning it uses the passive voice.
Supposed*
You had a grammatical error and I had to fix it considering you’re an English teacher.
C) Tying the paragraph together is definitely one of them. If I had to choose another one I would include B) Emphasizing the important points.
It's definitely D.
It's for sure not C. And I've never read the full story, but this passage doesn't indicate a depressing mood of foreshadowing danger. And the vocabulary in the writing doesn't impact the story itself.
