The correct answer is c) solute.
In a solution, the substance that is dissolved is known as the solute. In the case of salt water, salt is the solute and is dissolved in water, which acts as the solvent. Together, they form a solution. This means that if you take a glass of salt water, the salt (solute) is literally mixed into the water (solvent) to create a uniform mixture, typically referred to as a solution.