Helmets help when there's a risk of falling or getting hit in the head, like in baseball, softball, biking, skiing, horseback riding, skateboarding, and inline skating. Make sure you wear a helmet that is made for the activity you are doing. And make sure you know how it is supposed to fit. In some states, the law says you have to wear a helmet while biking. Bike helmets should come with a special sticker from the U.S. Consumer Product Safety Commission (CPSC).
Based on the supporting details, what is a main idea of the excerpt?
Helmets are only necessary when there is a risk of falling.
Wearing a helmet guarantees one’s safety when playing sports.
One should wear a helmet to prevent injuries during sports activities.
Most states have laws about wearing helmets during sports activities.