Read these sentences from lines 44 through 47. "Sports-related brain injuries are also receiving more public attention because of the willingness of professional athletes to speak out. For example, more than 2,000 retired NFL players filed a lawsuit against football helmet maker Riddell® and the NFL for hiding information about the dangers of concussions and the consequences of hits to the head."

Which inference do these sentences best support?

A. Older helmets do not protect athletes from head injuries.
B. The problem of head injuries is not confined to student-athletes.
C. Professional athletes are reluctant to report head injuries during their careers.
D. Legal action is an effective way to discover information about the dangers of concussions.