Name three essential macronutrients and their primary roles in plant growth.

• A. Nitrogen for vegetative growth and chlorophyll synthesis; Phosphorus for energy transfer and root development; Potassium for water regulation and enzyme activation.
• B. Nitrogen for drought resistance; Phosphorus for leaf color; Potassium for seed germination.
• C. Nitrogen for water uptake and stomatal opening; Phosphorus for energy transfer and root development; Potassium for moisture regulation and enzyme activation.
• D. Nitrogen for disease resistance; Phosphorus for soil structure; Potassium for photosynthesis.

Answer: (C)

Macronutrients are needed in larger amounts by plants and each one supports key processes that drive growth. Nitrogen fuels the production of amino acids, proteins, and chlorophyll, which promotes vegetative growth and leaf efficiency. Phosphorus is central to energy transfer and storage (ATP) and to the development of roots and reproductive growth. Potassium helps regulate the plant’s water balance and activates many enzymes essential for metabolism and overall function.

The option that pairs nitrogen with growth and leaf function, phosphorus with energy transfer and root development, and potassium with moisture regulation and enzyme activation best reflects these primary roles. Other choices mix in traits that aren’t the main functions of these nutrients, such as linking nitrogen to drought resistance or leaf color, or attributing unrelated roles to phosphorus or potassium.