Why does an author use foreshadowing?

to spoil the story for audiences who dislike surprises

to prepare audiences for what will happen later

to provide a detailed summary about events to come

to allow audiences to visualize what is being described

a is the indefinite article

at nineteen years old, nicole c. kear's biggest concern is choosing a major--until she walks into a doctor's office in midtown manhattan and gets a life-changing diagnosis. she is going blind, courtesy of an eye disease called retinitis pigmentosa, and has only a decade or so before lights out. instead of making preparations as the doctor suggests, kear decides to carpe diem and make the most of the vision she has left. she joins circus school, tears through boyfriends, travels the world, and through all these hi-jinks, she keeps her vision loss a secret.

when kear becomes a mother, just a few years shy of her vision's expiration date, she amends her carpe diem strategy, giving up recklessness in order to relish every moment with her kids. her secret, though, is harder to surrender - and as her vision deteriorates, harder to keep hidden. as her world grows blurred, one thing becomes clear: no matter how hard she fights, she won't win the battle against blindness. but if she comes clean with her secret, and comes to terms with the loss, she can still win her happy ending

googles summry you can summarize this in your own words