What is the requirement for children using a booster seat?

The requirement for children using a booster seat is based on the child's weight and age, which is accurately represented in the correct choice. Children must be at least four years old and weigh at least 40 pounds to safely transition to a booster seat. This guideline is designed to ensure that a child is developed enough to be properly secured using the vehicle's seat belt system.

Using a booster seat helps position the seat belt appropriately across a child's body, reducing the risk of injury in a crash. The rules are structured to prioritize the safety of the child in the vehicle, as younger and lighter children may not be adequately protected with just the seat belt alone.

The other choices do not meet the necessary criteria because they either set the age or weight requirements too low or provide incorrect age limits for proper use of a booster seat. Understanding these guidelines helps caregivers make informed decisions about child safety in vehicles.