Answer:
Belt positioning booster seats.
Step-by-step explanation:
There are many types of car seats. Rear facing, convertible, booster seats are there according to the age of the babies. Rear facing are for infants, convertible are for toddlers and booster seats are usually for the children more than 6 yo 8 years of age. These booster seats can be secured with the car belts as well as the belts of the seats. Maintaining the position of the car seat is very crucial.
In this example, Ricky and Elena's son is 9 years old, so they should take booster seat for the car.