Given scientific fact as input, generate the question from this fact such that it can be answered from the input.

Example Input: A decline in blood flow to kidneys organs stimulates release of the enzyme renin, in turn stimulating the reabsorption of sodium and water.
Example Output: A decline in blood flow to what organs stimulates release of the enzyme renin, in turn stimulating the reabsorption of sodium and water?

Example Input: Compounds containing an atom of nitrogen element, bonded in a hydrocarbon framework, are classified as amines.
Example Output: Compounds containing an atom of what element, bonded in a hydrocarbon framework, are classified as amines?

Example Input: Mammalian sex determination is determined genetically by the presence of chromosomes identified by the letters x and y.
Example Output:
Mammalian sex determination is determined genetically by the presence of chromosomes identified by what letters?