Answer:
The author does not want the narrator's personality to interfere with the story.
Explanation:
The author's main objective is to develop a whole story from the begining to the end. The focus is on the events which may be unfolded through a long period of time. The narrator will try to be objective since the story is more important than the narrator's emotions.
Answer: A
Explanation: Just by looking at the title you know it’s about islands and climate change.
I think the correct answer is the third one, "I made the best brownies today!"
An unreliable narrator is a narrator whose credibility has been compromised. Since you can't tell if this narrator credibility has been compromised from a single sentence but need a whole text to develop such incredibility, I say this is unreliable because the narrator is giving its own opinion of something he/she has made, and you can't rely on he/she being imparcial.