question: Hint: Please answer the question and provide the correct option letter, e.g., A, B, C, D, at the end.
  Question: 已知：如图，△ABC中，AB＝AC，BD为∠ABC的平分线，∠BDC＝75°，则∠A的度数为（）
  Choices:
  (A) 25°
  (B) 35°
  (C) 40°
  (D) 45°