The sentence that helps readers determine the story’s setting is:
D) The morning mist was completely gone. The sun was strong and bright, intensifying the color of a row of potted marigolds on the front porch of one of the houses.
This sentence provides a description of the time of day (morning), weather conditions (morning mist gone, bright sun), and details about the environment (potted marigolds on the porch), all of which contribute to the setting of the story.