question: In triangle A B C, AB = AC. \angle C A B and \angle A B C are both 2 x degrees. A B and B C are 3 and 4 y - 5 inches, respectively. Find x.
  Choices:
  A:20
  B:30
  C:40
  D:50
query_wo: Please directly answer the question and provide the correct option letter, e.g., A, B, C, D.
  Question: In triangle A B C, AB = AC. \angle C A B and \angle A B C are both 2 x degrees. A B and B C are 3 and 4 y - 5 inches, respectively. Find x.
  Choices:
  A:20
  B:30
  C:40
  D:50
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: In triangle A B C, AB = AC. \angle C A B and \angle A B C are both 2 x degrees. A B and B C are 3 and 4 y - 5 inches, respectively. Find x.
  Choices:
  A:20
  B:30
  C:40
  D:50
question_for_eval: In triangle A B C, AB = AC. \angle C A B and \angle A B C are both 2 x degrees. A B and B C are 3 and 4 y - 5 inches, respectively. Find x.
  Choices:
  A:20
  B:30
  C:40
  D:50