One reason for making a new outline of your work while revising is to make sure that all the new and necessary information you need to edit and put in (or maybe delete as well) are included in your work. This is to minimize wasting of the time and leaving out important details in the revision.
Answer:
I believe the answer would be:
A. Note: This letter needs to be mailed immediately.
If a story has an unreliable narrator, you should still trust what they say, although you must take it with a grain of salt. The narrator could still be telling the truth, although if they are insane they may describe seeing a ghost when there wasn't really a ghost. An unreliable narrator does not create a fake story, only an unreliable story, where there may be holes or lies weaved into truth.
