Aradio station plays a commercial. it features a famous singer introducing herself and saying that she listens to the station. what propaganda technique is being used to convince you that the station is the best? facts and stats glittering generalities plain folks testimonial

The answer is Testimonials because the singer is giving a testimony by saying the station is the best.

It could not be facts or glittering generalities because those do not involve people.

("In promotion and of advertising, a testimonial or show consists of a person's written or spoken statement extolling the virtue of a product. The term "testimonial" most commonly applies to the sales-pitches attributed to ordinary citizens, whereas the word "endorsement" usually applies to pitches by celebrities. Testimonials can be part of communal marketing. Sometimes, the cartoon character can be a testimonial in a commercial.") from Wikipedia

expository writing is one of the most common types of writing.

you need need more details so we can understand what your asking us.