Answer:
D. Using humor to make the topic more interesting.
Step-by-step explanation:
The most unique rhetorical device here could be using humor to make the idea more impressive and intriguing as this may turn fatal too sometimes. The use of humor may lead to diminish the significance of the work and consequently disappoint the audience and vary their final opinion. Thus, employing humor is very risky yet the most exclusive as not every speaker dares to take this liability. This distinct device can only be employed by those who have the confidence and ability to convince the readers by not letting the speech being monotonous and stodgy, and lightening up the mood by applying humor.