question: If the circumference of the large circle is 36 and the radius of the small circle is half of the radius of the large circle, what is the length of the darkened arc?
  Choices:
  A.10
  B.8
  C.6
  D.4
  E.2
  
query_wo: Please directly answer the question and provide the correct option letter, e.g., A, B, C, D.
  Question: If the circumference of the large circle is 36 and the radius of the small circle is half of the radius of the large circle, what is the length of the darkened arc?
  Choices:
  A.10
  B.8
  C.6
  D.4
  E.2
  
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: If the circumference of the large circle is 36 and the radius of the small circle is half of the radius of the large circle, what is the length of the darkened arc?
  Choices:
  A.10
  B.8
  C.6
  D.4
  E.2
  
question_for_eval: If the circumference of the large circle is 36 and the radius of the small circle is half of the radius of the large circle, what is the length of the darkened arc?
  Choices:
  A.10
  B.8
  C.6
  D.4
  E.2
  