Answer:
By sympathizing with the young couple.
Explanation:
The whole story is narrated mainly in third person. There are a few times where the narration shifts into first person but the narrator does not seem to be another character in the story and does not expand his view beyond Della's.
If you want to make a past emphatic tense, you need to use the verb DID + the present form of that particular verb. Assuming that the verb you need is TELL, the correct answer here would be did tell.
We did tell you how to find our house.
He feared Heracles because he did such an impossible task
