What message about hard work does the author imply?

Responses
A Nadia's dog helped her to perform well in spite of her stage fright.Nadia's dog helped her to perform well in spite of her stage fright.
B Nadia's study habits helped her to perform well in spite of her stage fright.Nadia's study habits helped her to perform well in spite of her stage fright.
C Nadia's rigorous practicing allowed her to perform well in spite of her stage fright.Nadia's rigorous practicing allowed her to perform well in spite of her stage fright.
D The attention from the audience allowed Nadia to perform well in spite of her stage fright.

C Nadia's rigorous practicing allowed her to perform well in spite of her stage fright.