the answer is c good luck mate
If this is how you've presented the question, Its a bit hard to answer it when one hasn't read these books. It'd be best if you'd put both books into a summary for us to go based off of, at most.
Answer:
Tara would have sung in the competition if she had not gotten sick.
Explanation:
This type of mood states conditions that are opposite of the reality or even imaginary.
Hope this helps you!
B. Say to himself or herself, “Is that really true?