In this task, you are given a sentence and a question, you would be asked to create the answer which is contained in the sentence provided.
One example: Sentence: Having white fur trait would a cat most likely inherit from its parents. Question: Which trait would a cat most likely inherit from its parents?
Solution is here: having white fur
Explanation: The given output is correct as the answer provided is from the scientific fact stated

Now, solve this: Sentence: Air can be separated into several elements. Question: Which of the following substances can be separated into several elements?
Solution:
air