Fix the sentence by following the apostrophe rule.

The books story was pretty exciting, even though its cover was not.

a. The books' story was pretty exciting, even though its cover was not.
b. The book's story was pretty exciting, even though it's cover was not.
***c. The book's story was pretty exciting, even though its cover was not. ***
d. The books story was pretty exciting, even though it's cover was not.

You're right.

The correct answer is c. The book's story was pretty exciting, even though its cover was not.

To fix the sentence, we need to apply the apostrophe rule correctly. The word "books" in option a is incorrect because it implies multiple books, but the sentence is referring to a single book. Therefore, we need to use the singular possessive form "book's" to indicate that the story belongs to the book.

Option b is incorrect because "it's" is a contraction of "it is" and does not show possession. We need to use the possessive form "its" to indicate that the cover belongs to the book.

Option d is incorrect because "it's" is again a contraction of "it is" and does not show possession. We need to use the possessive form "its" to indicate that the cover belongs to the book.

The correct sentence with proper use of apostrophe is:

c. The book's story was pretty exciting, even though its cover was not.