Answer: Different narrators can change the trajectroy of the story with their own thoughts about the matter. This creates Tone and Mood.
Step-by-step explanation:
For example, this may occur as the narrator can see into other people's thoughts, and create a mood that is somber or happy. The tone is how the author writes, and can be forceful or another emotion. If the tone if first person, the narrator will have a view on the matter as with their own opinion, and may even change in their opinion throughout the story. Hope this helps.