question: The graph, which is a piecewise function and passes through the origin, shows Frank'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:Frank starts off at a constant speed and then increases his speed at a steady rate
  B:Frank starts off by increasing his pace gradually and then maintains a constant speed
  C:Frank starts off by increasing his pace gradually, then increases his pace at a faster rate as he sees his arch rival beside him and finally increases his pace at a more gradual pace
  D:Frank 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, which is a piecewise function and passes through the origin, shows Frank'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:Frank starts off at a constant speed and then increases his speed at a steady rate
  B:Frank starts off by increasing his pace gradually and then maintains a constant speed
  C:Frank starts off by increasing his pace gradually, then increases his pace at a faster rate as he sees his arch rival beside him and finally increases his pace at a more gradual pace
  D:Frank 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, which is a piecewise function and passes through the origin, shows Frank'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:Frank starts off at a constant speed and then increases his speed at a steady rate
  B:Frank starts off by increasing his pace gradually and then maintains a constant speed
  C:Frank starts off by increasing his pace gradually, then increases his pace at a faster rate as he sees his arch rival beside him and finally increases his pace at a more gradual pace
  D:Frank increases his speed at a constant rate throughout the entire race
question_for_eval: The graph, which is a piecewise function and passes through the origin, shows Frank'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:Frank starts off at a constant speed and then increases his speed at a steady rate
  B:Frank starts off by increasing his pace gradually and then maintains a constant speed
  C:Frank starts off by increasing his pace gradually, then increases his pace at a faster rate as he sees his arch rival beside him and finally increases his pace at a more gradual pace
  D:Frank increases his speed at a constant rate throughout the entire race