Answer:
The conservation of fresh water would be the "most energy-efficient way" to make sure the "planet has adequate water" for drinking.
Step-by-step explanation:
- Freezing ocean water, in the first place, would not be a good option as the ocean water would still be saline even after freezing it.
- On the other hand, it would neither be feasible nor would it be economical to freeze the ocean water.
- Though reverse osmosis and distillation are efficient methods of water treatment, it would not be possible to treat water enough to fulfill the drinking water need of the entire planet.