cooking sugar on a stove pouring sugar through a screen dissolving a sugar cube in water crushing a sugar cube into pieces
I gave my students this multiple choice question: Which action will cause sugar to form a new substance?

Only one answer is correct among these 4 choices:
- cooking sugar on a stove
- pouring sugar through a screen
- dissolving a sugar cube in water
- crushing a sugar cube into pieces

Could you tell me which one is correct?

cooking sugar on a stove