Which of the following is a micronutrient essential to plants?

• A. Iron (Fe)
• B. Nitrogen (N)
• C. Phosphorus (P)
• D. Potassium (K)

Answer: (A)

Micronutrients are minerals needed in small amounts, and iron is one of them. Iron is essential for plants because it helps with chlorophyll production and various enzyme reactions that drive photosynthesis as a metal cofactor. Nitrogen, phosphorus, and potassium, by contrast, are macronutrients required in much larger quantities to support growth, energy transfer, and overall development. A common iron deficiency shows up as yellowing between the veins of young leaves, reflecting impaired chlorophyll synthesis even when macronutrients are available. So iron fits the definition of a micronutrient and is the correct choice.