Overexposure to certain wavelengths of

Answer choices

1. A

   Correct61% picked this

   There is no evidence that there are wavelengths of sunlight that lead to both

   Why this is right

   This hurts the argument because the recommendation was definitively connected to melanoma. The argument said, "For this reason, doctors urge we put on adequate sunblock." All we're told about adequate sunblock is that it prevents sunburn. But according to this answer, preventing sunburn has nothing to do with preventing melanoma (it's different wavelengths of sunlight). So this answer weakens the argument by making the premise in the final sentence be irrelevant to the Goal of the Recommendation. The doctors are recommending adequate sunblock as a means of avoiding melanoma, and they've defined adequate sunblock as "anything that prevents sunburn", but that means that there could be a sunscreen that just blocks sunburn wavelengths (so it would qualify as adequate sunblock) but doesn't block melanoma wavelengths (since they are entirely distinct).

   Skill tested: Weaken · how this choice captures the argument's function is the move to repeat next time.

   61%
2. B

   Weaker Than Correct Answer9% picked this

   There are people who have allergic reactions to certain chemicals found

   This weakens somewhat, because it points out a potential disadvantage of recommending sunblock to everyone (some people will likely have allergic reactions). This isn't a huge weakener, since people would obviously rather risk an allergic reaction, until they find a sunblock that works for them, than to risk getting melanoma. And so the impact of this answer is not nearly as strong as the correct answer, which made the argument's premise seem downright irrelevant to the conclusion.

   9%
3. C

   No Impact9% picked this

   Many sunblocks need repeated applications to remain effective for a significant

   This isn't really an objection. It's not posing much of a hurdle to this plan's success. It's just saying that many sunblock's would need to be periodically re-applied, if you're going to be out in the sun for a long time. Okay, so re-apply the sunblock. That's no big objection. The doctors defined adequate sunblock with a weird noun, "any preparation that prevents sunburn". That noun seems to be kind of like "any regimen / protocol", which could certainly include the idea of needing to periodically re-apply another 'dose' of sunblock.

   9%
4. D

   Too Vague9% picked this

   Toxins contained in certain chemical compounds also

   There's a nonzero chance that the chemical compounds this answer is talking about are in sunblock, in which case this answer would be suggesting that sunblock itself could lead to melanoma. But this answer just says "certain chemical compounds". There are potentially millions of those. We don't know whether this answer is saying anything about any ingredient in sunblock. We could consider this whisper of doubt/concern if all the other answers did nothing or went the wrong way, but we have better options.

   9%
5. E

   Unclear Impact13% picked this

   Sunburns appear immediately after exposure to the sun but melanoma appears years

   This does seem to point a potentially meaningful distinction between sunburn and melanoma, but it's not clear how this distinction relates to the recommendation to put on adequate sunblock. Since sunburns apparently show up earlier than melanoma, then preventing sunburns could still potentially prevent melanoma (if the two are connected). This answer isn't really giving us any reason to think that sunburns and melanoma are or aren't connected.

   13%