Does the airbag replace the seat belt?
A)No, it is a safety system complementary to the seat belt.Correct
B)Yes, if we drive within a built-up area, but not if we drive outside it.
The airbag is a non-mandatory passive safety device, unlike the seat belt, which is mandatory. In the event of a frontal collision, if we do not wear the seat belt even if the car has an airbag, we may suffer very serious injuries.