<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A first-year medical student is analyzing data in a nationwide cancer registry. She identified a group of patients who had recently undergone surgery for epithelial ovarian cancer and achieved a complete clinical response to chemotherapy. Some of these patients had been scheduled to receive annual abdominal CTs while other patients had not been scheduled for such routine imaging surveillance. The medical student then identified a subgroup of patients who have developed recurrent metastatic disease despite their previous complete clinical response to chemotherapy and surgery. She compared patients who were diagnosed with metastatic cancer during routine follow-up imaging with patients who were diagnosed with metastatic cancer based on clinical symptoms at routine follow-up history and physical exams. She found that the average survival of patients who underwent routine imaging was four months longer than the survival of their peers who were diagnosed based on history and physical exam. Which of the following is a reason why these results should be interpreted with caution?? A: Observer bias, B: Lead-time bias, C: Confounding bias, D: Length-time bias, E: Surveillance bias,  <response>: This is a question about potential biases in a medical study comparing survival times between two groups of patients with recurrent ovarian cancer. One group was diagnosed through routine imaging surveillance, while the other group was diagnosed based on clinical symptoms. The key thing to analyze is why the observed difference in survival times between the two groups may be biased or misleading. Some potential biases to consider are lead-time bias, length-time bias, and surveillance bias. Lead-time bias occurs when earlier diagnosis through screening leads to the appearance of longer survival time, even if it doesnt actually prolong life. Length-time bias is related and occurs when screening preferentially detects slower-growing cancers that have better prognosis. Surveillance bias occurs when increased medical surveillance in one group leads to earlier diagnosis and the appearance of longer survival.B: Lead-time bias 