At what age can children start using a booster seat?

Answer: B — 4 years

Children can start using a booster seat at around 4 years old, as this is the age when many children have outgrown their forward-facing car seats but are still not large enough to safely use an adult seat belt alone. Booster seats are designed to elevate a child so that the vehicle's seat belt fits properly across their body, specifically across the shoulder and lap, helping to reduce the risk of injury in the event of a crash. Using a booster seat until a child reaches the appropriate height and weight for a standard seat belt is crucial for their safety. This recommendation aligns with guidelines from safety organizations, which stress the importance of keeping children in a booster seat until they are 4 feet 9 inches tall, usually around 8 to 12 years of age. By beginning to use a booster seat at 4 years, parents help ensure that their children are secured safely while traveling in a vehicle.