Final answer:
When buying a 10-year-old car, the verbal guarantee of the condition by the owner is not important. Instead, having it checked by a mechanic, test-driving, and researching its value are essential steps.
The correct option is b.
Step-by-step explanation:
The aspect not important when considering purchasing a 10-year-old car from an individual is the owner's verbal guarantee that the vehicle is in good condition.
Unlike the other options, which involve personal verification and research, a verbal guarantee is not reliable.
You should always have the car checked by a reliable mechanic, test-drive the car, and research the car's value in resources like the Kelley Blue Book to make informed decisions.
The correct option is b.