I think the answer to this question is A
Answer: A. Your tone.
Explanation:
It would mosty likley be your tone because if the crowd were good you woudl want to have their anttention and if they weren't such a good crowd you would get frustrated because that woudl be annoying. So for that sake it would be your tone that woudl chang einfront of an audience.
Thrilled. This is the only option that was related/positive among the other choices. Overjoyed means happy, yet the three other choices were negative