The right answer is B. nonfiction film presented through narration and video footage.
Here is a brief explanation of documentaries:
Documentary is an artistic production, as a rule a nonfiction film, which is characterized mainly by the commitment of the exploration of reality. The documentary is the genre of cinema that comes closest to electronic journalism. Although it has the characteristic of transforming banal into cinematographic spectacle, it is still poetic and subjective, bearing the mark of its author. In other words, despite being a team production, the documentary is authored by the director of the film.
