Because ethylene dibromide, a chemical usedto fumigate grain, was blamed for the high rate of nerve damage suffered bypeople who work in grain-processing plants, many such plants switched to otherchemical fumigants two years ago. Sincethen, however, the percentage of workers at these plants who were newlydiagnosed with nerve damage has not dropped significantly. Therefore, either ethylene dibromide waswrongly blamed or else the new chemicals also cause nerve damage.
Which of the following is an assumption onwhich the argument depends?
A If the new chemicals cause nerve damage, the nerve damage caused would be different from any nerve damage that ethylene dibromide may cause.
B There are no chemical fumigants that are completely safe for workers in grain-processing plants.
C If ethylene dibromide causes nerve damage, it does not take two years or longer for that damage to become detectable.
D Workers at grain-processing plants typically continue to work there even after being diagnosed with nerve damage.
E Workers at grain-processing plants that still use ethylene dibromide continue to have a high rate of nerve damage.
