Answer:
Highlight the impact of Kettering's invention on society
Step-by-step explanation:
You can use process of elimination on this. It's not the first one, because the author praises his invention and says it helped by "contributing to the growth of the U.S", we can eliminate the second one because he isn't writing about how sophisticated cars were, only about the invention. That leaves the last one, which makes the most sense and has been checked.