Question type:
Flaw
Argument CoreConclusionSunscreen doesn't effectively block cancer causing UV radiation
EvidencePeople who USE sunscreen tend to average as much skin cancer as people who DON'T USE sunscreen.
ANALYSIS
This conclusion is anti-causal. He's saying sunscreens DON'T help block UV, lessening cancer risk.
To argue with him, we need to argue the anti-conclusion, that "Sunscreen DOES block cancer-causing UV".
Okay, if that's our position, then how are we going to explain the fact that people who use sunscreen have about the incidence of skin cancer as people who don't use sunscreen?
How can sunscreen be helping if people are getting the same results by not using it?
(Some people will think of an answer here, some will be stumped. If you think of an answer, then you have a good pre-phrase to scan for. If you don't think of an answer, then you're hoping an answer choice will light the lightbulb of "how can sunscreen be helping the people using it if they're getting the same results as people who don't use it?")
ANSWERS
(A) takes for granted + EXTREME (common wrong answer choice pattern). He doesn't have to assume that sunscreen has NO other benefits. We're not debating whether sunscreen is worth wearing, in a broad sense. We're debating whether it diminishes your skin cancer risk.
(B) This distinction would hurt the author if we knew that people using sunscreen got the same number of skin cancers, but of much less severity, than do people who don't use sunscreen. We don't know that sunscreen users have less severe skin cancer, so we'd be adding that crucial component, but this answer DOES seem to create some doubt. Keep it.
(C) fails to consider + OUT OF SCOPE (common wrong choice pattern)
This conclusion is purely about sunscreens that ARE designed to prevent UV radiation.
(D) "many scientific studies" gave us this evidence. Aren't scientific studies "Possible to challenge"? Isn't that the whole peer-review process? These are quantifiable statistics ... you do/don't wear sunscreen ... you do/don't have skin cancer. The only sort of evidence that would be impossible to challenge would be something like a subjective opinion, or eyewitness testimony from someone who's now dead.
(E) If people who use sunscreen are way more exposed to UV radiation than those who don't use sunscreen, then we shouldn't expect equal results from these two groups.
If neither group wore sunscreen,
the sun-exposed group would get more skin cancer than
the less sun-exposed group.
Since wearing sunscreen brings the sun-exposed group down to the less sun-exposed group's rate of skin cancer, we're effectively proving that sunscreen DOES lessen your risk of skin cancer.
LSAT likes to do this with anti-causal arguments.
You attempt to show that X does nothing, because people who do X have the same outcome as people who don't do X.
But you have to assume that those two groups were fair to compare in the first place. If the two groups of people have a meaningful difference, their initial reference point can be very different from each other.
Therefore, achieving the SAME outcome from two DIFFERENT starting points means that something DID change.
Check out this nearly identical LSAT question from test 64:
https://www.manhattanprep.com/lsat/foru ... t5440.html