question: The graph, which is a piecewise function and passes through the origin, shows John's speed while he is competing in a walking race, the x-axis representing Time and the y-axis representing Speed. Which situation corresponds to the graph?
  Choices:
  A:John increases his speed for the first half of the race and then decreases his speed in the second half
  B:John increases his speed at a constant rate throughout the entire race
  C:John starts off by increasing his pace gradually and then stops as he trips over a stick, but then recovers and is able to increase his speed steadily until the end of the race
  D:John starts off by increasing his pace gradually and then continues to steadily increase his pace at a faster rate
query_wo: Please directly answer the question and provide the correct option letter, e.g., A, B, C, D.
  Question: The graph, which is a piecewise function and passes through the origin, shows John's speed while he is competing in a walking race, the x-axis representing Time and the y-axis representing Speed. Which situation corresponds to the graph?
  Choices:
  A:John increases his speed for the first half of the race and then decreases his speed in the second half
  B:John increases his speed at a constant rate throughout the entire race
  C:John starts off by increasing his pace gradually and then stops as he trips over a stick, but then recovers and is able to increase his speed steadily until the end of the race
  D:John starts off by increasing his pace gradually and then continues to steadily increase his pace at a faster rate
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, which is a piecewise function and passes through the origin, shows John's speed while he is competing in a walking race, the x-axis representing Time and the y-axis representing Speed. Which situation corresponds to the graph?
  Choices:
  A:John increases his speed for the first half of the race and then decreases his speed in the second half
  B:John increases his speed at a constant rate throughout the entire race
  C:John starts off by increasing his pace gradually and then stops as he trips over a stick, but then recovers and is able to increase his speed steadily until the end of the race
  D:John starts off by increasing his pace gradually and then continues to steadily increase his pace at a faster rate
question_for_eval: The graph, which is a piecewise function and passes through the origin, shows John's speed while he is competing in a walking race, the x-axis representing Time and the y-axis representing Speed. Which situation corresponds to the graph?
  Choices:
  A:John increases his speed for the first half of the race and then decreases his speed in the second half
  B:John increases his speed at a constant rate throughout the entire race
  C:John starts off by increasing his pace gradually and then stops as he trips over a stick, but then recovers and is able to increase his speed steadily until the end of the race
  D:John starts off by increasing his pace gradually and then continues to steadily increase his pace at a faster rate