Which solar term began to dry salt?

A, the principle of salt drying in seawater is to evaporate seawater to obtain salt crystals; Sun and wind can change the solution from unsaturated to saturated, not from saturated to unsaturated, so the option expression is wrong.

B, sodium chloride is not affected by temperature. Increasing the temperature will not reduce the solubility of sodium chloride in water, so the option is incorrectly stated.

C, the sun and wind make the water in seawater evaporate, not sodium chloride, so the option is incorrectly stated.

D, the solubility of salt is little affected by temperature, and the salt obtained from salt solution mainly uses sunlight and wind to evaporate water, so that sodium chloride is crystallized out, so the option statement is correct.

So choose D.