question: As shown in the figure, PA and PB are tangent to circle O at points A and B respectively, the tangent EF of circle O intersects PA and PB at points E and F respectively. If the length of PA is 2.0, then the perimeter of triangle PEF is ()
  Choices:
  A:8
  B:6
  C:4
  D:2
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, PA and PB are tangent to circle O at points A and B respectively, the tangent EF of circle O intersects PA and PB at points E and F respectively. If the length of PA is 2.0, then the perimeter of triangle PEF is ()
  Choices:
  A:8
  B:6
  C:4
  D: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: As shown in the figure, PA and PB are tangent to circle O at points A and B respectively, the tangent EF of circle O intersects PA and PB at points E and F respectively. If the length of PA is 2.0, then the perimeter of triangle PEF is ()
  Choices:
  A:8
  B:6
  C:4
  D:2
question_for_eval: As shown in the figure, PA and PB are tangent to circle O at points A and B respectively, the tangent EF of circle O intersects PA and PB at points E and F respectively. If the length of PA is 2.0, then the perimeter of triangle PEF is ()
  Choices:
  A:8
  B:6
  C:4
  D:2