Jenna is a talented singer. her singing is commendable when she is well rehearsed and is performing with her school choir group. in such situations, she is moderately aroused and fairly relaxed. however, when jenna's friends are around, she gets overly aroused and anxious. in such situations, she finds it hard to focus and often makes mistakes. which of the following psychological principles can be used to explain the rationale behind jenna's performance? a. yerkes-dodson law. b. clark hull's theory. c. james-lange theory. d. cannon-bard theory.