The common theme touched upon in both the letter and the short story excerpt is A) the difficulty of saying goodbye.
In the excerpt from "Young Goodman Brown," the farewell between Goodman Brown and his wife Faith is filled with emotion, and she expresses her desire for him to stay, highlighting the difficulty of separation. Similarly, in the letter, the author expresses feelings of unease and discontent when experiencing a lack of a goodbye from her partner, indicating that saying farewell is significant to her. Both pieces reflect the emotional weight and importance of goodbyes in relationships.