The third answer is your best choice.
Answer:
A. Somber/Sadness
Explanation:
The sigh implies this answer, and excitement and anger do not make sense in this context.
To be is a form of a future verb. so that means all of these will have "will be" in front of them. For example, "Even if wild animals (will be born) in a zoo, it is still cruel to keep them in a small enclosure."
