Audience is the people who are being entertained, or are watching. I don't really understand your question, is there any answer choices? that would be very helpful.
Which part? If you mean the first part, then "The shelves were empty" is an independent clause.
Just answer the question and then make the next sentences about the main ideas of your next paragraphs including the conclusion
It is effective because it uses a rhetorical device to appeal to logic
The answer to your question is D.
