Task: Question Answering
Input (English): Dawn brought a chocolate bar for lunch, but the chocolate melted in her backpack. Dawn wants to perform a scientific investigation to determine the reason her chocolate bar melted in her backpack. Which hypothesis should Dawn use for her investigation?  
 (A) Chocolate will taste better when melted. (B) Chocolate will taste the same even when melted. (C) If the chocolate is broken then the chocolate will melt. (D) If heat is added to chocolate then the chocolate will melt.
Output (English): D