In a Study of Concussions Occurring in the National Football

Multiple Choice

In a study of concussions occurring in the National Football League (NFL) ,losing consciousness for more than one minute was highly correlated with the athlete's needing more than a week of rest to recover.From this,we can infer that

A) it is likely that the NFL is not following proper evaluation procedures.
B) losing consciousness for less than a minute is considered a Grade 1 concussion,which requires little rest before returning to play.
C) losing consciousness for less than a minute is considered a Grade 2 concussion,which requires at least one week of rest before returning to play.
D) losing consciousness for any period of time is a Grade 3 concussion,but if unconsciousness lasts less than a minute,play can be resumed after a week without symptoms.