The correct answer to the question above is the (c.) anyone's completes the sentence. Miranda says that the outcome of the race is anyone's guess. Since Miranda is referring to anyone that is involve (not particularly in it) in the race, it means should refer anyone to anyone's.
I believe that the closest synonym for the word overwhelmed is awestruck. It isn't jubilant, because that means happy. And overwhelmed isn't necessarily happy, it is just a strong emotion. Flattered and gracious just don't fit here.
Answer:
Maria feels proud of herself when she works hard and gets good grades in her classes.
Explanation: