The author sets off the passage's final phrase with an em dash primarily to A.)It reviews the authors line of reasoning by listing the main points of the argument.
B.)it engages the audience his sympathies by suggesting parallels between Rowling and her fictional hero
C.) it contextualizes the argument by explaining the challenges that Rowling faced as a woman author.
D.) it enhances the authors credibility by relating a little known anecdote about Rowlings early interest in fantasy fiction.
E.) it captures the audiences attention by presenting an Imaginary scenario about how Rowling created Harry Potter.

I answered in the comments to your previous question, B. Although not sure why there is two different questions and the answer options are the same

the answer should be b.

explanation:

it should be b because she researched before writing so it would be in past tense. "the author researches her subject before she had written the first draft.

either online or traditional classroom can work for students. which is better will depend on students and teacher. students may have trouble following a lesson in classroom while they can study at their own pace online. other students may have trouble staying focus on their own in online classes. teachers are more used to classroom teaching but they may also be more worry about their jobs teaching online classes and work harder.