I am not sure what section you are referring to but probably because the sun is a star.
Answer:
1. I don't agree with this statement. Sometimes panic can determine life or death. But so can too much panic.
2. I don't agree with this statement. 300 people, and counting, have died while trying to reach the top. It's cold and dangerous.
3. I agree with this statement. Deserts are very hot. It's hard to find shelter, food, and water as well.
The answer to fill in the blank would be B) Thesis statement because the thesis is like the message the author is trying to send to his readers so they can comprehend his or her text.