That would be the boy in the red shirt. Hope this helps, and have a nice day ;)
The paragraph contains a simile
If a politician tells you that "everybody is joining his team", then this is called a Bandwagon Propaganda. Bandwagon is a persuasive technique of propaganda, wherein others are encouraged to do the same act as what others do because the majority of the people agreed in joining them. An example of a Bandwagon technique is, "Most of the people are voting for this candidate. We should vote for him too."
A. Miss Grundy told Archie that he really spent a lot of time on his homework. As to what made her say this, it wasn't explicitly explained until the later parts of the conversation. Archie took this as a positive remark.
B. Archie asked Miss Grundy if his homework was decent. Archie was pleased that her teacher knew he spent time on his homework and asked if his work pleased her.
C. Miss Grundy really meant that Archie spent a lot of time on his homework because of the numerous stains from a whole evening's worth of snacks. It didn't mean that Archie's work was good, just that he spent a lot of time on it.
