question: As shown in the figure, AB and CD are the two diameters of circle O, chord DE parallel  AB, arc DE is the arc of 50.0, then angle BOC is ()
  Choices:
  A:115°
  B:100°
  C:80°
  D:50°
query_wo: Please directly answer the question and provide the correct option letter, e.g., A, B, C, D.
  Question: As shown in the figure, AB and CD are the two diameters of circle O, chord DE parallel  AB, arc DE is the arc of 50.0, then angle BOC is ()
  Choices:
  A:115°
  B:100°
  C:80°
  D:50°
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: As shown in the figure, AB and CD are the two diameters of circle O, chord DE parallel  AB, arc DE is the arc of 50.0, then angle BOC is ()
  Choices:
  A:115°
  B:100°
  C:80°
  D:50°
question_for_eval: As shown in the figure, AB and CD are the two diameters of circle O, chord DE parallel  AB, arc DE is the arc of 50.0, then angle BOC is ()
  Choices:
  A:115°
  B:100°
  C:80°
  D:50°