I think the best statement that explains why the author included both of these scenes in the story is that its purpose is to develop the relationship between the old man and the boy. The answer is letter D.
A positive tone (if this is the one your looking for) is a happy tone of voice. If you have a positive tone ion your voice it is cheerful and nice.
A negative tone is an unhappy tone of voice. If you have a negative tone in your voice it is sad and not that great.
Hoped I helped!
The answer should be D) Unfamiliar technical language.