The sentence which is the author’s claim is Sentence 3
This refers to an unverified statement about a particular thing which needs to be validated with a supporting evidence.
It is important not to be confused by a claim, and the reason for a claim (supporting evidence).
The author talks about the importance of using a seat belt and then gives a reason for his claim (supporting evidence) using statistical data on how the use of seat belts have saved lives.
In conclusion, the claim of the author in the sentence is Sentence 3.
Read more about claims here:
https://brainly.com/question/13628349