It was the 1930s when the period of To Kill a Mockingbird set.
I have never read what you are asking, but just by looking at it, I would assume that he is stereotyping Dutch people, because he is calling Black Dog an insult, which is "son of a dutchman".
ANSWER: D
Reasoning: Adults are less likely to be entertained by talking animals because they know that animals can’t possibly talk. But children, on the other hand, believe whatever they read.
