volume of water in the xylem flow of necessary nutrients response to environmental factors rate of photosynthesis in leaves
I gave my students this multiple choice question: When a tree suffers from a decreased ability to transport materials within the phloem, what is directly impacted?

Only one answer is correct among these 4 choices:
- volume of water in the xylem
- flow of necessary nutrients
- response to environmental factors
- rate of photosynthesis in leaves

Could you tell me which one is correct?

flow of necessary nutrients