Question

add concrete data to support your arguments, lend credibility to your speech, and help show the significance of the points you are trying to make.
a. examples
b. narrations
c. testimonies
d. statistics

Explanation:

Statistics are numerical data that provide objective and quantifiable support. Examples, narrations, and testimonies are more anecdotal or qualitative. Statistics add credibility by presenting hard - data.

Answer:

d. Statistics