Answer:
poisonous because it is another word for toxic
I think the one that learn the least is : The narrator's aunt. She kept making unreasonable accusation throughout the story. One of it was that she believed that the burglar has been coming to her house every night for the last 40 years. i might say that the one that learn the most would be the narrator himself.
Hope this helps
I think its B unless you're talking college wise then it would be C.
I'd recommend reading a review on the book describing the plot, and see what you can get from that.