through a chemical called chlorophyll by using photosynthesis through a system of tubes by converting water to food
I gave my students this multiple choice question: Which of the following best explains how stems transport water to other parts of the plant?

Only one answer is correct among these 4 choices:
- through a chemical called chlorophyll
- by using photosynthesis
- through a system of tubes
- by converting water to food

Could you tell me which one is correct?

through a system of tubes