Answer: The correct answer is A.
Explanation: In a solution, the substance which is in larger proportion is called as a solvent and the substance which is in smaller proportion is called as a solute.
When we mix a powdered Gatorade in the water, the Gatorade is present smaller proportion and hence will be considered as a solute in a solution and water is present in larger proportion and will be considered as solvent in a solution.
Hence, the correct option is A.