Advertisers, as Well as Waiters and Waitresses, Have Found a Technique

Advertisers, as well as waiters and waitresses, have found a technique for quickly increasing their trustworthiness in the eyes of an audience. It involves:

A) arguing earnestly for the virtues of their product.
B) saying how intelligent they think the audience is.
C) arguing initially against their own interests by mentioning a minor problem with their product.
D) saying how dependent they are on the audience.
E) arguing first for the virtues of their product and then mentioning a minor problem with it.