question: The graph shows Bart's speed while he is competing in a walking race. Which situation corresponds to the graph?
  Choices:
  A:Bart increases his speed for the first half of the race and then slows in the second half
  B:Bart starts off by increasing his pace gradually and then maintains a constant speed
  C:Bart starts off at a constant speed and then increases his speed at a steady rate
  D:Bart increases his speed at a constant rate throughout the entire race
query_wo: Please directly answer the question and provide the correct option letter, e.g., A, B, C, D.
  Question: The graph shows Bart's speed while he is competing in a walking race. Which situation corresponds to the graph?
  Choices:
  A:Bart increases his speed for the first half of the race and then slows in the second half
  B:Bart starts off by increasing his pace gradually and then maintains a constant speed
  C:Bart starts off at a constant speed and then increases his speed at a steady rate
  D:Bart increases his speed at a constant rate throughout the entire race
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: The graph shows Bart's speed while he is competing in a walking race. Which situation corresponds to the graph?
  Choices:
  A:Bart increases his speed for the first half of the race and then slows in the second half
  B:Bart starts off by increasing his pace gradually and then maintains a constant speed
  C:Bart starts off at a constant speed and then increases his speed at a steady rate
  D:Bart increases his speed at a constant rate throughout the entire race
question_for_eval: The graph shows Bart's speed while he is competing in a walking race. Which situation corresponds to the graph?
  Choices:
  A:Bart increases his speed for the first half of the race and then slows in the second half
  B:Bart starts off by increasing his pace gradually and then maintains a constant speed
  C:Bart starts off at a constant speed and then increases his speed at a steady rate
  D:Bart increases his speed at a constant rate throughout the entire race