Which of the following is a restriction for using airbag seat belts?

Airbag seat belts are designed with safety mechanisms that include enhanced protection for adults in the event of a crash. The restriction regarding pets in carriers is vital because an unrestrained pet can become a projectile during a collision, potentially resulting in injury to both the animal and passengers. In contrast, it is important that any pets being transported are safely secured to avoid interference with the airbag seat belt system and to ensure that the vehicle's safety features work effectively.

The other options do not accurately reflect restrictions associated with the proper use of airbag seat belts. Wearing masks is not a safety regulation related to airbag technology, while children under certain ages may require specific child safety seats rather than modifications to airbag seat belts. Additionally, the use of two seat belt extenders is not typically allowed as it could compromise the integrity of the restraint system. Understanding these restrictions helps ensure that all passengers, including pets, are secure and protected.