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.

[EX Q]: Fact: male dogs use natural aphrodisiacs in urine to mark their territory. 
Question: what do male dogs use in their urine to mark their territory?
[EX A]: natural aphrodisiacs.

[EX Q]: Fact: A person's elbow straightens when muscles antagonistic to biceps contract. 
Question: A person's elbow straightens when muscles antagonistic to what contract?
[EX A]: biceps.

[EX Q]: Fact: A prism is used to split light into colors. 
Question: What does a prism split light into?
[EX A]:
colors.