The correct answer is: D. A picture of a popular movie star shaking hands with the president.
Indeed, according to Herbert George Wells, the best propaganda is the one that is invisible, undetectable, which does not look like propaganda at all. A popular movie star is associated with values which public opinion approves of, by having such person shake hands with the president; people associate the president with this popular actor who in their view represents such values. This deprives them of their critical thinking since they have let propaganda activate an emotional response in them. This propaganda is extremely effective since the act of shaking hands is a required social ritual and the event where the two shale hands is framed as an innocent coincidence.
