A

B. The author develops the marital harmony theme through plot details.

Explanation:

Look Homeward, Angel: A Story of the Buried Life (1929) is the novel by Thomas Wolfe. Eugene Gant, the main character of this piece of literature, is considered the author’s depiction of himself. In his book, Thomas Wolfe tried to portray the American experience. The key themes of the novel are human existence, family relationships, and friendships. Look Homeward, Angel: A Story of the Buried Life has received positive reviews for its emotional power and Thomas Wolfe’s brilliance.

The marital harmony between Eugene Gant and his wife Luisa is developed through a fictional plot with unrealistic elements. Thomas Wolfe used such an approach to show how relationships affect individuals’ existence.

"Look Homeward, Angel" scene.
Source: http://rapidrivermagazine.com