Saki provides several details that mark the transformation of the men from revenge-seeking enemies to peace-seeking friends. The first detail can be identified in Ulrich's feeling of pity for Georg that inspires him to make a sudden offer of wine to his enemy. Though Georg responds badly to Ulrich's attempt at peace, the narrator of the story reports that Ulrich's animosity begins to ease. The second detail that marks the transformation is Ulrich's speech to...
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.
I think it’s the second option but I’m not sure