Weaken --> identify the conclusion "PZ 1000 is one of the safest cars available today" <-- it says PZ 1000 is one of the safest among all cars available today.Background information: the report compares PZ 1000 with cars in "its class" --> so the conclusion should be narrowed down to be PZ 1000 is one of the safest cars in "its class"C: PZ 1000 class is more likely to be involved in accidents --> so even PZ 1000 is the safest one in its class, it doesn't mean PZ 1000 is the safest among all cars