The crowds of people who were climbing up the hill suddenly caught sight of the peach,a terrible monster,plunging down upon them.
While all the answers have a degree of validity, option C is the most correct one. Flashbacks are essentially a narrative technique that allows the author to break the usual monotony of storytelling by jumping back and forth between events and turning a linear story (from point A to point B) into a circular one (from point B to point C through point A, for instance).
Over exaggerated
In the context of this passage, which is talking about how Facebook is attempting to cut down on incorrect, fake, or 'sensationalized' news, the word clearly means news that is not true or over exaggerated in a way that makes it 'click bait'-something that isn't clear, objective content.
