Answer:
Your answer would be that the bolded portion of the sentence should be inside quotation marks.
Step-by-step explanation:
"Laughing prophet of doom" are the words used by The New York Times when referring to Vonnegut. That part of the sentence should be inside quotation marks.
We use quotation marks when we want to use someone else's words in our writing. What is more, the sentence above contains a direct quote as it reports the exact words by the newspaper. You should always put the quote between quotation marks unless you paraphrase it.