Question

add concreteness, add interest, and help to maintain attention from the audience.
a. examples
b. narrations
c. testimonies
d. statistics

Explanation:

Examples can make ideas more concrete, engaging, and hold the audience's attention by providing real - life or illustrative cases. Narrations tell stories which may not always be as directly concrete as examples. Testimonies are statements from individuals mainly for credibility. Statistics are numerical data which might not always add the same level of concreteness and interest as examples.

Answer:

A. Examples