A drop of water in a tin of sugar: Which one's the solvent, the sugar or the water?
You could imagine stirring the sugar enough for the water molecules to be uniformly distributed throughout - it would then be homogeneous.  

However, even then, to refer to the mixture as a solution of water in sugar is unhelpful, not least because referring to a slightly damp solid as a solution will only confuse.  A definition needs to be useful, as well as being a set of criteria to be met.

Consider adding more water, and stirring till uniformly distributed.  At some point, the mixture will become a thick syrupy liquid.  Add yet more, and it will eventually resemble an ordinary solution.  At what arbitrary point do you say one is a solution of the other?

As a device to get students thinking about the interactions that take place when a solid dissolves in a liquid, or a liquid in another liquid, it's an excellent question, but not one that has either a right or a wrong answer, other than "neither", or indeed "both".

What is definitely wrong is to insist that there's only one right answer to the question.