Passage Summary: A disease kills 2 percent of the dogs that get it, but the vaccine only kills 0.02 percent of dogs that get the shot, so the shot is the better choice.

Conclusion: It is safer for a dog to be vaccinated than to remain unvaccinated.

Reasoning: The death rate for dogs that catch the disease is 1 in 50, while the death rate from vaccine complications is only 1 in 5,000.

Analysis: To evaluate this argument, we must identify the missing variable in the risk-benefit calculation: the probability of exposure. The argument compares the risk of death *given* infection versus the risk of death *given* vaccination, but it ignores how likely a dog is to catch the disease in the first place. If the disease is so rare that only 1 in a million dogs ever encounters it, then the 1 in 5,000 risk from the vaccine is actually much more dangerous. Look for an answer that asks about the frequency of the disease in the general population.