question: Q:A prospective cohort study is conducted to evaluate the risk of pleural mesothelioma in construction workers exposed to asbestos in Los Angeles. Three hundred construction workers reporting current occupational asbestos exposure were followed alongside 300 construction workers without a history of asbestos exposure. After 8 years of follow-up, no statistically significant difference in the incidence of pleural mesothelioma was observed between the two groups (p = 0.13), even after controlling for known mesothelioma risk factors such as radiation, age, and sex. Which of the following is the most likely explanation for the observed results of this study?? 
  {'A': 'Length-time bias', 'B': 'Lead-time bias', 'C': 'Latency period', 'D': 'Observer effect', 'E': 'Berkson bias'},