Over the Course of 5 Years, a Pediatric Endocrinologist Has

Over the course of 5 years, a pediatric endocrinologist has seen a marked increase in the prevalence of depression among patients with obesity in her practice.  She partners with a pediatric psychiatrist to devise a short screening test for depression for this specific population.  The new screening test is found to be 90% sensitive and 84% specific.  If this test is used on a sample of patients with obesity in which 35% are known to have depression The authors of the study decide to conduct an ancillary statistical analysis in which a second cohort of workers employed in the manufacture of domestic textiles is used as the population of reference.  Based on the study results from the first cohort of vinyl chloride workers, which of the following is the most likely reason for the ancillary analysis?

A) All-cause mortality among the vinyl chloride workers is statistically lower than among the general population.
B) Compared to the general population, vinyl chloride workers had a nonstatistically significant association with mortality due to melanoma and lung cancer.
C) Considering a cohort of domestic textile workers reduces the possibility of contamination bias.
D) Misdiagnosis of early angiosarcoma of the liver might have influenced the association between vinyl chloride exposure and hepatocellular carcinoma.
E) The expected number of deaths among domestic textile workers will be greater than in the general population.