question: Hint: Please answer the question and provide the correct option letter, e.g., A, B, C, D, at the end.
  Question: As shown in the figure, P is a point outside ⊙O, PA and PB intersect ⊙O at two points C and D respectively. It is known that the central angles of ⁀AB and ⁀CD are 90.0 and 50.0 respectively, then ∠P = ()
  Choices:
  (A) 45°
  (B) 40°
  (C) 25°
  (D) 20°