purification of an ore the growth of a crystal a liquid becoming a solid sedimentation of granules
I gave my students this multiple choice question: Pat dissolves some table salt in water. She then puts a drop of the water on a microscope slide and turns on the lamp. As the water evaporates, Pat observes small cubic structures being formed. What process is Pat seeing through the microscope?

Only one answer is correct among these 4 choices:
- purification of an ore
- the growth of a crystal
- a liquid becoming a solid
- sedimentation of granules

Could you tell me which one is correct?

the growth of a crystal