Question ID:PT47 S3 Q14 Passage:Overexposure to certain wavelengths of strong sunlight is the main cause of melanoma, a virulent form of skin cancer.  For this reason, doctors now urge everyone to put adequate sunblock on skin exposed to strong sunlight.  Adequate sunblock, according to doctors, is any preparation that prevents sunburn even if the person is exposed to strong sunlight for a significant length of time. Stem:Which one of the following, if true, most weakens the recommendation that people wear adequate sunblock? Correct Answer Choice:AChoice A:There is no evidence that there are wavelengths of sunlight that lead to both sunburn and melanoma. Choice B:There are people who have allergic reactions to certain chemicals found in many sunblocks. Choice C:Many sunblocks need repeated applications to remain effective for a significant length of time. Choice D:Toxins contained in certain chemical compounds also cause melanoma. Choice E:Sunburns appear immediately after exposure to the sun but melanoma appears years after repeated exposures.