The description of the garden creates a picture of a peaceful place to rest and contributes to the narrative by setting the tone and establishing the setting.
The description of the garden contributes to the narrative by creating a picture of a gentle and peaceful place to rest. Option B, "It creates a picture of a gentle and peaceful place to rest," is the best statement that explains how the description of the garden contributes to the narrative.
The detailed description of the garden sets the tone and atmosphere of the story, providing a contrast to the strangeness of the house.
It also helps to establish the setting and creates a sense of tranquility and beauty in the midst of other elements of the story.