Answer:
A
Step-by-step explanation:
a. What happens in the story and why it happened
b. How the author causes the reader to be engaged with the story
c. What caused the author to write this story
d. What happens when a reader finishes a good book
The cause is what happens in the story and the effect is figuring out why it happened or what happens after.
It is very possible the answer could be B so I would think of picking that but my first thought was A.