Nouns ending in "o" preceded by a vowel form their plurals by adding "s" or "es"? (it can only be one or the other.)

Announcer two: ladies and gentlemen, following on the news given in our bulletin a moment ago, the government meteorological bureau has requested the large observatories of the country to keep an astronomical watch on any further disturbances occurring on the planet mars. due to the unusual nature of this occurrence, we have arranged an interview with noted astronomer professor pierson, who will give us his views on the event. in a few moments we will take you to the princeton observatory at princeton, new jersey. we return you until then to the music of ramón raquello and his orchestra. the passage is from the transcript of the radio adaptation of the war of the worlds by h. g. wells. instead of including expert interviews, h. g. wells uses a narrator to tell about an alien invasion that occurred a few years earlier. by including expert interviews, how does the radio broadcast change the story most effectively? o. a. it puts the story in the past tense, increasing its personal tone. o o b. it makes the broadcast sound more like a fictional story. o o c. it makes the broadcast sound like a news report. o d. it makes the story sound less believable by changing who presents the story's details.