LR Insights: What do you guys think is meant by "prevention"?

Hey guys,

This is a burning question that's been bothering me since the beginning of my LR prep.

If you have seen PT64 S1 Q13 (joggers question) and PT73 S4 Q3 (skin cancers question) or would like to check them out, please continue reading.

In PT64 S1 Q13, the argument concludes that stretching doesn't help prevent injury because the group that stretched before jogging had the same number of injuries as those who didn't.
This is a weaken question.

We have Trap Answer Choice E, which states that in some forms of exercises stretching before engaging in an activity can reduce the severity of injuries. It is easy to eliminate E on the basis of "some forms of exercise" because we do not know that such a case includes jogging. But what if E had specifically mentioned jogging? Would it weaken the argument? Can the severity of an injury be a factor that contributes to the effectiveness of its prevention?

Similarly, in PT73 S4 Q3, the argument concludes that sunscreen lotions aren't effectively preventing UV rays causing skin cancer because the average number of the people who get skin cancer is as great for people using sun lotions as those who don't.
This is a flaw question.
Trap Answer Choice B says that the argument fails to see the difference between the number of cases and the severity of the cases in evaluating the effectiveness of skin cancer prevention.

One clear way to eliminate B is to realize that B does not pinpoint which group's skin cancers were more severe. If B had said that the argument fails to consider that the group without sun lotion had more severe cases of skin cancer, would it be the flaw of the argument?

I think the decision to accept modified versions of both PT73 S4 Q3 and PT64 S1 Q13 depends on how we understand the definition of prevention. To evaluate whether prevention of a disease/injury occurred effectively, is it sufficient to ONLY focus on the number of injuries/disease prevented OR do we also need to take into account whether any reduction in the severity of such disease/injury occurred?

In my opinion, measuring the severity of an injury does matter in assessing the effectiveness of a preventive measure.
If a thousand people who used sunscreen lotion developed stage 1 skin cancer but the same number of people who didn't use sunscreen lotion developed stage 4 skin cancer, the argument would be weakened because the sunscreen lotion indeed was effective in blocking a worse form of skin cancer. It would be unreasonable to say that sunscreen lotion wasn't effective in that case.

All in all, what is meant by effective prevention? Does it have it to be complete 100% prevention (as in no instances of injuries, whether severe or light) to be properly called effective prevention?

Thank you so much for reading my painful thought process. Please help!