Final answer:
The cat in the passage symbolizes Zeena's presence and possibly her authority, as it occupies her chair and observes Ethan and Mattie with puzzlement, reflecting the tension between them. Option E. represents Zeenas continued presence in the room is the correct answer.
Step-by-step explanation:
In the context of the passage from Ethan Frome by Edith Wharton, the inclusion of the cat most likely represents Zeenan's continued presence in the room. Mattie's substitution for Zeena in her rocking-chair, followed by the cat's action of taking the same chair and observing the scene, suggests a symbolic representation of Zeena's watchful presence and possibly her authority within the household.
Moreover, the cat's puzzled observation mirrors the characters' unease, acting as a silent observer to the undercurrents of tension between Ethan and Mattie.