Final answer:
The primary purpose of the rising action in a story is to build suspense and tension by introducing secondary conflicts and delaying the resolution of the main conflict, compelling the reader to continue reading.
Step-by-step explanation:
The complications that create a story's rising action serve mainly to build suspense by putting off a resolution of the conflict. During the rising action, secondary conflicts are introduced, and tension is created, leading up to the climax of the story. These events are essential as they fully develop the conflict, engage the reader by increasing tension, and drive the narrative forward by setting the stage for the eventual resolution.