In the story "The Open Window," the room and its furnishings play a significant role in shaping Nuttel's assumptions about the strangers who live there. The presence of an open window and the various descriptions of the room suggest a certain openness and perhaps a haunting past, which leads Nuttel to make particular assumptions about Mrs. Sappleton's character and circumstances.
Nuttel, observing the room, assumes Mrs. Sappleton must either be married or widowed due to the context clues provided, such as the open window symbolizing a departure or longing for someone who is absent. This assumption shapes his understanding of the family dynamics in the household and sets him up for the surprise twist of the story.
Therefore, the most accurate response would be: He assumes Mrs. Sappleton must either be married or widowed.