heat the solution cool the solution add more sugar to the pan take some water out of the pan
I gave my students this multiple choice question: A student is dissolving sugar in water to make candy. She notices that sugar lumps are forming at the bottom of the pan. What could she do to help more of the sugar dissolve?

Only one answer is correct among these 4 choices:
- heat the solution
- cool the solution
- add more sugar to the pan
- take some water out of the pan

Could you tell me which one is correct?

heat the solution