Smoking participants of a cohort study are more likely to drop out.It is known that the effect of asbestos on getting cancer is much stronger among smokers.When analyzing data for this study,researchers find no association between asbestos and cancer.A potential explanation for the results of the study is

A) confounding.
B) effect modification.
C) selection bias.
D) information bias.
E) specificity of association.

Selection Bias

A distortion in statistical analysis resulting from the method of collecting samples, leading to an unrepresentative sample and misleading results.

Cohort Study

An observational study in which a defined group of people (the cohort) is followed over time to study the incidence of disease or various outcomes.

Asbestos

A group of naturally occurring fibrous minerals known for their resistance to heat, chemicals, and electricity, historically used in construction but hazardous to health.