The writer John Barth suggested that

A) only writers can make sense of their lives as stories.
B) life is a Bildungsroman.
C) "life imitates art."
D) each of us is the hero of his or her own story.

John Barth's suggestion that each of us is the hero of his or her own story implies that our lives can be seen as narratives with us as the central characters. This idea has been explored in various forms of literature, from memoirs and autobiographies to novels and plays, where characters often struggle to define themselves and their place in the world. Therefore, the best choice is D.