The number of different synthetic chemical compounds that are known to be carcinogenic but are nonetheless used as pesticides, preservatives, or food additives is tiny compared to the number of nonsynthetic carcinogenic compounds widely found in plants and animals. It is therefore absurd to suppose that the rise in the cancer rate in recent decades is due to synthetic carcinogens.
The reasoning above is most vulnerable to criticism on the grounds that it overlooks the possibility that
A． the rise in the cancer rate in recent decades is due to increased exposure to nonsynthetic pollutants
B． the rise in the cancer rate in recent decades is due to something other than increased exposure to carcinogens
C． some synthetic chemical compounds that are not known to be carcinogenic are in other respects toxic
D． people undergo significantly less exposure to carcinogens that are not synthetic than to those that are synthetic
E． people can vary greatly in their susceptibility to cancers caused by nonsynthetic carcinogens