All of these discussion topics are open ended. What you decide to write about is entirely up to you. In order to receive full points, it should be clear to me that you have read and understood the chapter. Here are some suggestions on how to compose your post:
Write about a specific part of the chapter and how this relates to a current event, why is this chapter included and what is its importance? How do you feel about this chapter, what are the implications? Do you have anything else to add to this chapter? If the chapter was particularly complicated, you could summarize the key points in your post.
It is considered plagiarism to use any material that is not your own without citing where that material came from. This includes websites, blogs, online comments, and other outside material. It is OK to use outside material but you must cite when you do! The word count refers to material you wrote only, it does not include quotes from other authors or citations. You do not need to cite the online textbook in this assignment.