Appositive is the answer. Hope it helped
I think in this case the prepositional phrase would be early.
My personal opinion to what the answers are:
Readers are uneasy with the narrator's growing instability,
Readers question the narrator's ability to act rationally,
Readers understand that the account given by the narrator is true.
I hope this helped, again, this is only my opinion to what I believe the answers are.
