The correct answer is C) The words trumpet, honor, and knelt create a tone of respect.
The statement that best explains how word choice establishes tone is "The words trumpet, honor, and knelt create a tone of respect."
The moment you read the sentences that include those words, you feel the ceremonial tone of the statement. Read it: "After the trumpet was sounded and the flag folded, a member of the honor guard knelt in front of my frail." These words imply respect, honor, salutation, and appreciation.
The article "Veterans Appreciate Our Gratitude, But What They Need Most Is Our Help" mentions the importance of giving support to the US Veterans that had fought in the war defending the nation, and not only in homages but in a way that can really help them to have a better living.