Nitrogen increases protein production in plants. Nitrogen decreases protein production in plants. Nitrogen decreases the effectiveness of photosynthesis. Nitrogen increases the effectiveness of photosynthesis.
I gave my students this multiple choice question: Which best explains the importance of nitrogen in the cycling of energy and matter?

Only one answer is correct among these 4 choices:
- Nitrogen increases protein production in plants.
- Nitrogen decreases protein production in plants.
- Nitrogen decreases the effectiveness of photosynthesis.
- Nitrogen increases the effectiveness of photosynthesis.

Could you tell me which one is correct?

Nitrogen increases protein production in plants.