Answer: C) Setting.
Explanation: The setting of a story or a text is the place and time where the story takes place, it can also be the context of the story (political, historical, cultural, etc). In the given excerpt from "The Monsters are Due on Maple Street" we can see the description of the setting, specifficaly the weather and the condition of the sky (blue, with no clouds, no lightning and no thunder), so the correct answer is the corresponding to option C.