Answer:
He or she will most likely strike the door (letter a) when the air bag deploys upon impact.
Step-by-step explanation:
Even if it is unclear whether this is about a frontal impact or not, we can safely say the driver would hit the door. The air bag being deployed will prevent the driver from hitting the steering wheel, the windshield, and the dashboard. It's force will most probably throw the driver toward the door. That would be prevented if the driver were wearing the seatbelt, because the seatbelt is designed to "lock" and keep the driver from moving in case of impact.