Question

should be used when you want to reinforce the importance and significance of your arguments, especially when you are not an expert on your topic. be sure to stress the competence and lack of bias of your sources, and emphasize their recent nature.
a. examples
b. narrations
c. testimonies
d. statistics

Explanation:

Testimonies from competent, unbiased, and recent sources can reinforce argument - significance, especially when the speaker isn't an expert.

Answer:

c. Testimonies