Mandatory seatbelt laws have
a. cost lives
b. saved lives
c. impacted driver behavior
d. all of the above

B. saved lives

Explanation:

All traveling passengers should wear Seatbelts. Especially the passengers occupying the front seats, together with the drivers, are at high risk of getting injuries in case of any accidents, and the seatbelts are not fastened. Therefore, seatbelts are very useful in matters of safety while on the road. Seatbelt implementation has dramatically improved and saved many passengers from accidents and even death.  

However, making each person adapt to wearing seatbelts has not been easier because many always forget to ignore on purpose.

answer; exaggerate what you believe is the deception and state it, hoping that the other will jump in to "correct" the statement;