No, Use tone, the viewpoint character’s attitude, in every scene to deepen the reader’s connections to the events of that scene and to the character. While the characters feelings is what is affected by the tone.
The subject is defined as the "doer of an action". In this case, the answers would be C and D. So, who is only eight years old? The subject, that is, "my brother". Who is fascinated by bridges? The subject, that is, "he". He is used here only so as not to repeat "my brother" all over again, but they have the same meaning.
I think the answer is
to encourage people to eat healthy meals
