Answer:
i) valid
Step-by-step explanation:
The research only included car owners (and their cars) that suspected that auto repair shops had not done their job properly. The 42% of fraud rate is applicable to that specific population which is car owners that suspect auto repair shops have committed fraud. It is not representative of the general population of all the car owners whose cars have been repaired.
It is like making a research in a university campus and saying that 99% of the US population buys college books. Maybe 99% (or even 100%) of all college students buy college books, but the rest of the population doesn't and they do not have a reason to do so either.