An athlete's arousal level refers to

a. how well rested the athlete is before competition.
b. the "mind-set" of the athlete in reference to competition and intensity of the exercise or sport.
c. the methods by which the athlete prepared him/herself for competition.
d. the type of equipment the athlete uses during competition.

I believe the correct answer is option B. An athlete's arousal level refers to the "mind-set" of the athlete in reference to competition and intensity of the exercise or sport. The "mindset" is related to the athlete's mental and physical focus to a certain activity. The arousal level can be considered as the capacity of the athlete to do certain activities without any hesitation and with determination.  

 An athlete's arousal level refers to the "mind-set" of the athlete in reference tocompetition and intensity of the exercise or sport.