Why do claims need support or evidence?

Which words or phrases from this passage best demonstrate logos?

The institute of international research is holding its annual convention. this year more than 500 scholars have been invited to hear research reports on many timely topics. approximately 250 big name scientists will be winging their way to washington, d.c. how can the underlined sentence be revised so that it fits the tone of the passage? a) approximately 250 people will be in washington, d.c. b) approximately 250 bigwigs will be flying to washington, d.c. c) approximately 250 science people will be going to washington, d.c. d) approximately 250 well-known scientists will be arriving in washington, d.c.

Why is it important to be aware of you audience's interests? a. so that you can teach them new information thy didn't know b. so that you can use opposite ideas in order to shock them c. so that you can use the most effective strategy to persuade them d. so that you can pretend to like the same things and get them to trust you