Final answer:
The writing type best exemplified by the prompt to analyze the structure and characteristics of the author's style in response to "The Adventures of Tom Sawyer" is descriptive.
Step-by-step explanation:
The writing type that is best exemplified by the prompt asking students to analyze the structure and characteristics of the author's style in response to "The Adventures of Tom Sawyer" is b) Descriptive.
This is because when analyzing the text's structure and characteristics, students would be describing and discussing the various elements that make up the author's style, such as the use of language, narrative techniques, and the overall organization of the text.