Not all mixtures can be classified as solutions because C. not all mixtures have solutes and solvents.
You can answer this using the process of elimination. You know the answer cannot be A. because compounds are mixtures. It cannot be B. solutions are homogenous, so it wouldn't matter if the mixture was heterogeneous or not. It cannot be D. because mixtures have to be 2 or more substances.
The water cycle is driven primarily by the energy from the sun. This solar energy drives the cycle by evaporating water from the oceans, lakes, rivers, and even the soil. Other water moves from plants to the atmosphere through the process of transpiration.