题目内容：
Physiologically, why do we experience nervousness?
A.Nervousness is the physical syndromes one has when he or she is not confident enough.
B.Nervousness is felt because our body protection system is trying to tell us to run away from danger due to the imbalanced power distribution between the speaker and the audience
C.Nervousness is our physical response when we are put under the spotlight.
D.Nervousness is felt when we are not prepared for what's about to happen.
参考答案：