question: the distance CD from the top of the round arch bridge to the water surface is 8.0, and the arch radius OC is 5.0, so the width of the water surface AB is ()
  Choices:
  A:4m
  B:5m
  C:6m
  D:8m
query_wo: Please directly answer the question and provide the correct option letter, e.g., A, B, C, D.
  Question: the distance CD from the top of the round arch bridge to the water surface is 8.0, and the arch radius OC is 5.0, so the width of the water surface AB is ()
  Choices:
  A:4m
  B:5m
  C:6m
  D:8m
query_cot: Please first conduct reasoning, and then answer the question and provide the correct option letter, e.g., A, B, C, D, at the end.
  Question: the distance CD from the top of the round arch bridge to the water surface is 8.0, and the arch radius OC is 5.0, so the width of the water surface AB is ()
  Choices:
  A:4m
  B:5m
  C:6m
  D:8m
question_for_eval: the distance CD from the top of the round arch bridge to the water surface is 8.0, and the arch radius OC is 5.0, so the width of the water surface AB is ()
  Choices:
  A:4m
  B:5m
  C:6m
  D:8m