Question

What would the carbon dioxide part of a soft drink be classified as?

Answer 1

Answer: A. Solute
Solute is what is mixed into the solvent

Answer 2

Answer is: A. solute .

Solvation is the interaction of solvent (in this example water) with molecules or ions (in this example carbon dioxide)) in a solute.  

Solvent (usually a liquid, but can also be a solid or a gas) is a substance that dissolves a solute (dissolved in the solvent).

Solvent is always the same state of matter as the solution. In this example, soft drink is a liquid, so water is a solvent.