Answer: D) Humorous.
Explanation: The tone of a text or sentence is the author's or speaker's attitude towards the audience, the subject or even the characters of the text. There are many different kinds of tones, like: positive, negative, objective, sad, angry, etc. In the given passage by Oscar Wilde, the tone is clearly humorous, because he is saying that he is going to fight a duel to the death with his wallpaper.
