I think the 4th but I’m not 100% sure
I think that you just answered your own question in the question you asked.
The answer is C. hopefully i helped
Due to its energy consumption, desalinating sea water is generally more costly than fresh water from surface water or groundwater, water recycling and water conservation. However, these alternatives are not always available and depletion of reserves is a critical problem worldwide.[5][6] Desalination processes are usually driven by either thermal (in the case of distillation) or electrical (in the case of reverse osmosis) as the primary energy types.
Explanation:
The radical republican's reconstruction plan was the toughest on the south
