Which of the following documentary forms utilizes narration, most frequently as the "voice of God," along with visual evidence in order to explain a subject and persuade the audience of a key point?

The expository documentary form is characterized by its use of narration that often takes on the role of an authoritative voice, commonly referred to as the "voice of God." This narration guides viewers through the content, providing explanations and context that aim to clarify or persuade them about a particular subject or argument being presented. Visual evidence is utilized alongside this narration to support the claims made, strengthening the overall message.

In this format, the intention is to inform the audience and assert a strong viewpoint through a combination of spoken commentary and images or footage. This approach has been widely used throughout the history of documentary filmmaking, particularly in educational contexts and advocacy pieces, where presenting information in a clear, compelling manner is crucial.

The other forms—observational, participatory, and reflexive—approach documentary filmmaking differently. Observational documentaries aim to capture reality as it unfolds without intervention, participatory documentaries involve the filmmaker actively engaging with the subjects, and reflexive documentaries often focus on the filmmaking process itself and the relationship between the filmmaker and the audience. None of these employ the authoritative narration style central to expository documentaries.