B. The observers up front were asked to sit down so that the ones in the back could see. When you are talking about people, you use sit, not set.
Answer:
He hopes Mr. Turner can influence Mrs. Turner to visit less frequently.
Insert commas after "angry", "bitter", and "hateful" to separate them
Answer: D) The rules of communication
Explanation: Conventions in language are tests in which students learn how to communicate properly. Understanding language conventions lets people know how language works, how to successfully convey their message as they speak or write, and how to listen and interpret. Therefore; they are the rules of communication.
I would go with D for the first one and B for the second one.