Traditional "aged vinegar" production process there is a step called "winter fishing summer sun", refers to the winter fishing out of the vinegar in the ice, summer exposure to evaporate the water in

Traditional "aged vinegar" production process there is a step called "winter fishing summer sun", refers to the winter fishing out of the vinegar in the ice, summer exposure to evaporate the water in the vinegar, in order to improve the quality of the vinegar, the vinegar and the water in the vinegar, the vinegar and the water in the vinegar. A, the solute of vinegar is acetic acid is not alcohol, can not use the chemical formula of alcohol, so this option is optional.

B, the three states of matter is a physical change, water into ice is a physical change, so this option is not optional.

C, evaporation is the reduction of water, that is, the reduction of solvent, so that the solution becomes thicker, so this option is not optional.

D, winter fishing and summer sun are actually reducing the amount of solvent, is a way to increase the mass fraction of solute, so this option is not optional.

Therefore choose A

.