Task: Question Answering
Input (English): A piece of pine wood floats on the surface of a lake because the water exerts  
 (A) an upward force equal to the weight of the wood. (B) a downward force equal to the weight of the wood. (C) an upward force equal to the weight of the displacement water. (D) a downward force equal to the weight of the displacement water.
Output (English): C