Question ID:PT8 S1 Q13 Passage:Five years ago, during the first North American outbreak of the cattle disease CXC, the death rate from the disease was 5 percent of all reported cases, whereas today the corresponding figure is over 18 percent. It is clear, therefore, that during these past 5 years, CXC has increased in virulence. Stem:Which one of the following, if true, most substantially weakens the argument? Correct Answer Choice:DChoice A:Many recent cattle deaths that have actually been caused by CXC have been mistakenly attributed to another disease that mimics the symptoms of CXC. Choice B:During the first North American outbreak of the disease, many of the deaths reported to have been caused by CXC were actually due to other causes. Choice C:An inoculation program against CXC was recently begun after controlled studies showed inoculation to be 70 percent effective in preventing serious cases of the illness. Choice D:Since the first outbreak, farmers have learned to treat mild cases of CXC and no longer report them to veterinarians or authorities. Choice E:Cattle that have contracted and survived CXC rarely contract the disease a second time.