Which of the following is a macronutrient measured under India’s Soil Health…

Concept

Plant nutrients are classified by the quantities crops require. Primary macronutrients are nitrogen (N), phosphorus (P), and potassium (K).

Iron (Fe), copper (Cu), and boron (B) are micronutrients. A Soil Health Card reports several soil parameters, so the nutrient class—not mere inclusion in the test panel—must be identified.

Application

The three individually named substances—iron, copper, and boron—belong to the micronutrient group. Therefore, no individually named substance in the list is a macronutrient.

Contrast

• Iron (Fe): a micronutrient associated with chlorophyll formation and electron-transfer processes.

• Copper (Cu): a micronutrient involved in enzyme activity and redox processes.

• Boron (B): a micronutrient involved in cell-wall development and reproductive growth.

• None of these: represents the case in which none of the individually named nutrients belongs to the requested class.

Cross-check

The standard primary-macronutrient list is N, P, and K. None of N, P, or K appears among the individually named choices.

Hence, the answer is ‘None of these’.