Which method is commonly used in desalination to remove salt from seawater?

The correct option is Reverse osmosis. This answer is correct because it matches the approved learning objective to explain why desalination processes require large amounts of energy in the subtopic Potable water.

The correct option is Reverse osmosis. Reverse osmosis is correct because it directly supports the approved learning objective to explain why desalination processes require large amounts of energy. This belongs to the subtopic Potable water within Using the Earth's resources and obtaining potable water, so the explanation must stay tied to that curriculum context. The other options are incorrect because they either do not answer this learning objective, use a vague statement, or move away from Potable water.