Task: Question Answering
Input (English): When magnesium (Mg) metal is burned in the presence of oxygen (O?), magnesium oxide (MgO) is produced. The properties of magnesium oxide are different than the individual properties of magnesium and oxygen because magnesium oxide is      
 (A) a solution. (B) a mixture. (C) a compound. (D) an element.
Output (English): C