Answer: B. parallelism
Parallelism is a rhetorical device that repeats the same words or words with similar meanings in a certain pattern. This makes the text balanced and provides a particular rhythm to the speech, which can make it more persuasive. It is one of the most basic principles of rhetoric. In this case, by repeating the phrase "I don't believe" twice, Dr. King is increasing the rhythm and persuasiveness of his speech.
Answer: B. Mary Shelley wants to write a great Gothic story, but she can’t think of an idea.
Explanation: In the given excerpt from the introduction to "Frankenstein" by Mary Shelley, we can see how she describes her struggle to think of an idea to write a horror story compared to the ones she had read, but despite her efforts and constant thinking, she wasn't able to think of an idea of that she liked. So the correct option is B: Mary Shelley wants to write a great Gothic story, but she can’t think of an idea.