All of the following are examples of supporting materials, except:
a. Tina tells a story about a child who was killed in a drunk driving accident.
b. Jake summarizes the main points of his speech by restating his thesis in his conclusion.
c. Natalie quotes a physician who has studied cancer and treated patients for many years.
d. Josh explains that the US spends more on its military than 28 of the other top spending countries combined.