Which sentence provides a reason for the author’s claim?

(1) currently, different states have different laws regarding seat belt usage. (2) for instance, in some states, only people in the front seat of a vehicle are required to wear a seat belt. (3) all states should pass equally strict laws that make wearing seat belts mandatory for all passengers and drivers.

(4) statistics show that seat belts reduce serious crash-related injuries and deaths by fifty percent. (5) as a result of stronger regulations in various states, seat belt usage in the united states has dramatically increased in the past thirty years. (6) some people believe that the government does not have the right to force people to be safe, and that these laws are unfair. (7) the bottom line is that seat belts are proven to save lives; therefore, everyone should be forced to wear one if they want to travel by car or truck.

sentence 1
sentence 3
sentence 4
sentence 6