Given a fact, create a question that can be answered using the fact. Construct the question such that it is unambiguous, has a unique answer and the answer can be given using the fact.

Example Input: Fact: a plant requires sunlight to grow
Example Output: Which most directly requires sunlight to grow?

Example Input: Fact: a cavern is formed by carbonic acid in groundwater seeping through rock and dissolving limestone
Example Output: Kool-aid is a mix of what items as a solution?

Example Input: Fact: sunlight and rain can cause a rainbow
Example Output:
A rainbow is caused by rain and what?