In a certain state, the rate at which inhabitants of City X contract a certain disease is significantly lower than the rate at which inhabitants of City Y contract the disease. So if a couple originally from City Y relocates to City X and raises a family there, their children will be significantly less likely to contract this disease than they would have been if the
family had remained in City Y.
Which of the following statements, if true, would most significantly strengthen the conclusion drawn in the passage?
A. The rate at which inhabitants of City X contract the disease will increase as the overall population of City X increases.
B. In contrast to City Y, City X is characterized by an abundance of environmental factors that tend to inhibit the occurrence of the disease.
C. 23% of those inhabitants of City Y who move to City X live beyond the average life span of native inhabitants of City X.
D. Over the last 2 decades, the incidence of the disease has decreased in City Y but has remained unchanged in City X.
E. Studies indicate that the incidence of the disease among inhabitants of City X who move to City Y is roughly equal to that of inhabitants of City X who remain in CityX.