question: As shown in the figure, AB is tangent to circle O at point B, then angle C is equal to ()
  Choices:
  A:36°
  B:54°
  C:60°
  D:27°
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 is tangent to circle O at point B, then angle C is equal to ()
  Choices:
  A:36°
  B:54°
  C:60°
  D:27°
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 is tangent to circle O at point B, then angle C is equal to ()
  Choices:
  A:36°
  B:54°
  C:60°
  D:27°
question_for_eval: As shown in the figure, AB is tangent to circle O at point B, then angle C is equal to ()
  Choices:
  A:36°
  B:54°
  C:60°
  D:27°