potassium. phosphorus. carbohydrates. nitrogen.
I gave my students this multiple choice question: A brand of fertilizer claims that it contains all the chemicals a plant needs for rapid growth. It may be inferred that the fertilizer includes all these ingredients except

Only one answer is correct among these 4 choices:
- potassium.
- phosphorus.
- carbohydrates.
- nitrogen.

Could you tell me which one is correct?

carbohydrates.