Answer:
to support the presenter's ideas
Explanation:
C is the only sentence that uses commas correctly.
Answer:
The central idea is the “big point” or the most important idea that the writer is communicating to the reader. Often the reader can find the central idea just by looking at the title. For example, a passage titled: “Why Students Should Have Less Homework” will include reasons for that idea.
Extended metaphor is the answer
