A Novel Biomarker Has Been Demonstrated to Aid in the Early

A novel biomarker has been demonstrated to aid in the early diagnosis of non-small cell lung cancer. A preliminary review of a cohort trial of this novel test shows that its use increases lung cancer patient survival by 3 months when compared to individuals identified using conventional techniques. A subsequent investigation indicates no difference between the two groups in 6-month death rates. Which of the following variables best explains the study's findings?

A) Confounding
B) Lead-time bias
C) Length-time bias
D) Measurement bias
E) Observer bias
F) Rare disease assumption