Which sentence best supports the following main idea?

Sports today present safety risks to those involved.

A.
During the fall of each year, hours of televised football games enter our family rooms each weekend.
B.
Both horse owners and jockeys have been known to earn in the six figures annually from horse racing.
C.
Ice skating and hockey increase in popularity in children and young adults after each winter Olympics.
D.
Elbow, knee, and head injuries are common problems in many sports, from skateboarding to football.