Final answer:
The advertisement uses plain folk propaganda to convey relatability to the average person through the image of a man in everyday attire driving an older truck.
Step-by-step explanation:
An advertisement featuring a man in jeans and a t-shirt driving an older truck most clearly uses plain folk propaganda. This type of propaganda aims to appeal to the average person by depicting scenarios or individuals that seem relatable and down-to-earth. The message usually suggests that the product or idea being advertised is practical and sensible for the 'common person.
By portraying the man in everyday attire and an older vehicle, the advertisement is attempting to convey that the product is for everyone, especially for those who are not swayed by luxury or glamour.