A student combined 3.5 g sodium nitrate with 500 ml water and mixed them thoroughly. The resulting liquid was clear and colorless. Which of the following is true?
A. The sodium nitrate acted as a solute that dissolved in the water to make a solution.
B. The sodium nitrate acted as a solvent that dissolved in the water to make a solution.
C. The sodium nitrate reacted with the water to make a new substance.
D. The sodium nitrate fell to the bottom of the container, leaving the water clear and colorless.