Answer:
C). Concussion experts will help athletes only at organized games.
Step-by-step explanation:
In the given passage, the author substantiates all the given claims except for the claim regarding 'assistance of concussion experts being available to the athletes only at organized games.' There is no clear description regarding this claim that could verify or prove the reliability and convince the audience to believe in it. The other claims are supported with sufficient details that help establish the validity of the assertion and make them credible. Therefore, option C is the correct answer.