Write a correct answer to the given question based on its associated fact. Make sure that your answer is contained in the associated fact. Don't be creative and introduce any new word that is not mentioned in the associated fact! Remember that the associated fact has been rearranged to form the question. So, the correct answer words must lie within the associated fact. The correct answer can be a word, phrase, or even a sentence.

Example Input: Fact: animals use sound to find a mate. 
Question: What do animals use to find a mate?
Example Output: sound.

Example Input: Fact: pie charts are circle graphs. 
Question: Which is a circle graph?
Example Output: pie chart.

Example Input: Fact: Ocean thermal can be used to produce electricity. 
Question: what can be used to produce electricity?
Example Output:
ocean thermal.