Option B is the sentence that best states the theme of the story.
This is true because from the passage we discover that Coco and her mother tried as much as possible to be good neighbors. They showed that by preparing adequately to welcome their neighbor- they baked their special double chocolate cookies and took it to their neighbor in order to welcome her.
Even though the neighbor did not show the excitement they expected, they practically showed that people should try to be good neighbors.
