Using a natural voice is important than using an ideal voice. The passage tells us that many people that have the prestige of having a low voice, try to alter their voice, which can cause voice damage. While Choice C is correct, it is not the main idea, while Choice A would be.
1. Woodman Middle School is the oldest school in the city.
2. The American Automobile Association will be closed on Christmas.
3. Have you called the Chamber of Commerce about the parade?
4. Sara Donham is the minister at the Congregational Church.
5. When you visit Washington, D.C., be sure to visit the United States Senate.
I used to have a teacher who said this as well. The best way to understand would be to show examples of how to specify such terms as “stuff” and “things”. For instance: “The birds have lots of stuff.” That was not clear because the reader does not know what the “stuff” is. Instead, the text could be changed to: “The birds have lots of feathers.” Now the reader knows what the stuff is because it has been replaced with a more specific word. If you go over multiple examples in your head, it will become easier to comprehend and you will get used to doing it.