Answer:
The author's use of exposition creates a turning point in the story when Bella finds the message asking her to meet the letter writer in the park. This event introduces the main characters, Bella and her family, and sets the scene for the action that follows. The exposition also provides a resolution to the events that happen in the story: the identity of the letter writer. Furthermore, the author's use of exposition builds the tension that occurs in the story: the mystery behind the letters Bella finds.
Step-by-step explanation: